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Post by Night Ranger on May 19, 2015 11:25:10 GMT -5
This is a technical post for the PLL tech savvy and curious reader.
I was playing with an old 23 channel Kraco KCB-2310a with a PLL01a chip. That is not a typo. It is a PLL01a, and it preceded the PLL02a chip. This is a 16 pin PLL chip with 8 pins on each side. According to online documentation and "The CB PLL Data Book" by Lou Franklin, pins 8 through 15 represent programming pins P7 through P0" and pin 16 is "Vss" or ground. When I tried to manually map it out it quickly became obvious the book and online documentation was not correct. The various documentation also states this chip uses direct binary programming. This is also not correct.
So...the correct pinout is pins 16 through 9 represent programming pins P7 through P0 with pin 9 being the lowest power pin and pin 16 being the highest power.
The next odd thing is how it programs.
Pins 9 through 12 (four pins total) are BCD (binary coded decimal) and they represent the 10 kHz digit of the VCO downmix signal to the programmable divider in the pll01a chip. The next two pins (pins 13 and 14) are binary and represent the 100 kHz digit of the VCO downmix signal. That last two pins (pins 15 and 16) are binary and represent the MHz digit of the VCO downmix input signal to the programmable divider.
So...the VCO runs at 21 MHz approximately. It mixes with a crystal oscillator at 9.510 Mhz. This is how it works out.
On channel 13 the VCO is at 21.170 MHz. The 9.510 MHz crystal oscillator is doubled to 19.02 MHz. Next the 21.170 MHz VCO signal is mixed with the 19.02 MHz signal to give a down mix (difference) frequency of 2.150 Mhz. The 2.150 MHz signal is sent to the programmable divider on the PLL01a chip. You would think a straight binary N code would be 215 since 2.150 Mhz / 215 equals 10 kHz, but the decimal N code being programmed by the channel selector is 149. WTH?
Here is what happens. Pins 16 and 15 are programming pins P7 and P6. They are set to decimal 2 which is "10" in binary. Pins 14 and 13 are programming pins P5 and P4. They are set to decimal 1 which is "01" in binary. The last four pins (12 through 9) are programming pins (P3, P2, P1 and P0) and they are set to decimal 5 which is BCD (binary coded decimal) "0101". The reason I specify BCD for pins 9 through 12 is because they reset to all zeros after reaching decimal 9 or binary "1001" as you progress from channel 1 to channel 23.
So..the whole programming input for CB channel 13 looks like 10010101. From left to right the first two digits are decimal 2 for 2MHz. The second two digits are decimal 1 for 100 kHz, and the last four digits are decimal 5 for 50 kHz giving 2.150 Mhz.
Lets look a another channel.
The VCO downmix signal to the programmable divider for channel 23 is 2.290 MHz.
That means pins 16 and 15 will be set to binary "10" which is decimal 2 and represents the MHz number. Pins 14 and 13 will be set to binary "10" which is decimal 2 and represents the 100 Khz digit. The last four digits are BCD and are set to BCD "1001" which is "9" in decimal. Put it all together and it equals 2.290 MHz or "10101001".
Weird but interesting
: )
Night Ranger
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Sandbagger
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Post by Sandbagger on May 19, 2015 14:07:59 GMT -5
This is a technical post for the PLL tech savvy and curious reader. I was playing with an old 23 channel Kraco KCB-2310a with a PLL01a chip. That is not a typo. It is a PLL01a, and it preceded the PLL02a chip. This is a 16 pin PLL chip with 8 pins on each side. According to online documentation and "The CB PLL Data Book" by Lou Franklin, pins 8 through 15 represent programming pins P7 through P0" and pin 16 is "Vss" or ground. When I tried to manually map it out it quickly became obvious the book and online documentation was not correct. The various documentation also states this chip uses direct binary programming. This is also not correct. So...the correct pinout is pins 16 through 9 represent programming pins P7 through P0 with pin 9 being the lowest power pin and pin 16 being the highest power. The next odd thing is how it programs. Pins 9 through 12 (four pins total) are BCD (binary coded decimal) and they represent the 10 kHz digit of the VCO downmix signal to the programmable divider in the pll01a chip. The next two pins (pins 13 and 14) are binary and represent the 100 kHz digit of the VCO downmix signal. That last two pins (pins 15 and 16) are binary and represent the MHz digit of the VCO downmix input signal to the programmable divider. So...the VCO runs at 21 MHz approximately. It mixes with a crystal oscillator at 9.510 Mhz. This is how it works out. On channel 13 the VCO is at 21.170 MHz. The 9.510 MHz crystal oscillator is doubled to 19.02 MHz. Next the 21.170 MHz VCO signal is mixed with the 19.02 MHz signal to give a down mix (difference) frequency of 2.150 Mhz. The 2.150 MHz signal is sent to the programmable divider on the PLL01a chip. You would think a straight binary N code would be 215 since 2.150 Mhz / 215 equals 10 kHz, but the decimal N code being programmed by the channel selector is 149. WTH? Here is what happens. Pins 16 and 15 are programming pins P7 and P6. They are set to decimal 2 which is "10" in binary. Pins 14 and 13 are programming pins P5 and P4. They are set to decimal 1 which is "01" in binary. The last four pins (12 through 9) are programming pins (P3, P2, P1 and P0) and they are set to decimal 5 which is BCD (binary coded decimal) "0101". The reason I specify BCD for pins 9 through 12 is because they reset to all zeros after reaching decimal 9 or binary "1001" as you progress from channel 1 to channel 23. So..the whole programming input for CB channel 13 looks like 10010101. From left to right the first two digits are decimal 2 for 2MHz. The second two digits are decimal 1 for 100 kHz, and the last four digits are decimal 5 for 50 kHz giving 2.150 Mhz. Lets look a another channel. The VCO downmix signal to the programmable divider for channel 23 is 2.290 MHz. That means pins 16 and 15 will be set to binary "10" which is decimal 2 and represents the MHz number. Pins 14 and 13 will be set to binary "10" which is decimal 2 and represents the 100 Khz digit. The last four digits are BCD and are set to BCD "1001" which is "9" in decimal. Put it all together and it equals 2.290 MHz or "10101001". Weird but interesting : ) Night Ranger Extremely weird, although I have never had a first hand, hand's on experience with that PLL. I only know what I've read in the reference documentation, and none of that agrees with what you've observed. But I can't offer anything more than what is readily available on the internet. But obviously something is not the same.....
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Post by BBB on May 19, 2015 15:09:51 GMT -5
I can add that your Kraco radio was definitely making the trip up to S.E. PA today. Heard you Night Ranger sporadically in my mud-duck-pick-up-truck for the first half hour, then via a BIG SIGNAL around 3:30 PM. Who says roger beeps aren't good for anything I know 44 Dave (on his base) and Sandbagger (in his mobile) may have heard you also. Certainly hope to hear more quality propagation from the Carol inaPirate in the coming weeks! Sparky 775 out.
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Post by Night Ranger on May 19, 2015 17:22:52 GMT -5
This is a technical post for the PLL tech savvy and curious reader. I was playing with an old 23 channel Kraco KCB-2310a with a PLL01a chip. That is not a typo. It is a PLL01a, and it preceded the PLL02a chip. This is a 16 pin PLL chip with 8 pins on each side. According to online documentation and "The CB PLL Data Book" by Lou Franklin, pins 8 through 15 represent programming pins P7 through P0" and pin 16 is "Vss" or ground. When I tried to manually map it out it quickly became obvious the book and online documentation was not correct. The various documentation also states this chip uses direct binary programming. This is also not correct. So...the correct pinout is pins 16 through 9 represent programming pins P7 through P0 with pin 9 being the lowest power pin and pin 16 being the highest power. The next odd thing is how it programs. Pins 9 through 12 (four pins total) are BCD (binary coded decimal) and they represent the 10 kHz digit of the VCO downmix signal to the programmable divider in the pll01a chip. The next two pins (pins 13 and 14) are binary and represent the 100 kHz digit of the VCO downmix signal. That last two pins (pins 15 and 16) are binary and represent the MHz digit of the VCO downmix input signal to the programmable divider. So...the VCO runs at 21 MHz approximately. It mixes with a crystal oscillator at 9.510 Mhz. This is how it works out. On channel 13 the VCO is at 21.170 MHz. The 9.510 MHz crystal oscillator is doubled to 19.02 MHz. Next the 21.170 MHz VCO signal is mixed with the 19.02 MHz signal to give a down mix (difference) frequency of 2.150 Mhz. The 2.150 MHz signal is sent to the programmable divider on the PLL01a chip. You would think a straight binary N code would be 215 since 2.150 Mhz / 215 equals 10 kHz, but the decimal N code being programmed by the channel selector is 149. WTH? Here is what happens. Pins 16 and 15 are programming pins P7 and P6. They are set to decimal 2 which is "10" in binary. Pins 14 and 13 are programming pins P5 and P4. They are set to decimal 1 which is "01" in binary. The last four pins (12 through 9) are programming pins (P3, P2, P1 and P0) and they are set to decimal 5 which is BCD (binary coded decimal) "0101". The reason I specify BCD for pins 9 through 12 is because they reset to all zeros after reaching decimal 9 or binary "1001" as you progress from channel 1 to channel 23. So..the whole programming input for CB channel 13 looks like 10010101. From left to right the first two digits are decimal 2 for 2MHz. The second two digits are decimal 1 for 100 kHz, and the last four digits are decimal 5 for 50 kHz giving 2.150 Mhz. Lets look a another channel. The VCO downmix signal to the programmable divider for channel 23 is 2.290 MHz. That means pins 16 and 15 will be set to binary "10" which is decimal 2 and represents the MHz number. Pins 14 and 13 will be set to binary "10" which is decimal 2 and represents the 100 Khz digit. The last four digits are BCD and are set to BCD "1001" which is "9" in decimal. Put it all together and it equals 2.290 MHz or "10101001". Weird but interesting : ) Night Ranger Extremely weird, although I have never had a first hand, hand's on experience with that PLL. I only know what I've read in the reference documentation, and none of that agrees with what you've observed. But I can't offer anything more than what is readily available on the internet. But obviously something is not the same..... The first give away that something was wrong with online documentation was pin 16 is suppose to be Vss or ground. When I checked it with the volt meter it showed about +5 volts on it when the other meter lead was on ground. The voltage toggled as I turned the channel selector. Why would a PLL ground pin show voltage? The second red flag was when the lowest four programming pins kept counting up to 9 (1001) and then resetting to all zeros (0000) as I turned the channel selector. Straight binary does not do that, but BCD does. Night Ranger
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Sandbagger
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Post by Sandbagger on May 19, 2015 21:08:00 GMT -5
Extremely weird, although I have never had a first hand, hand's on experience with that PLL. I only know what I've read in the reference documentation, and none of that agrees with what you've observed. But I can't offer anything more than what is readily available on the internet. But obviously something is not the same..... The first give away that something was wrong with online documentation was pin 16 is suppose to be Vss or ground. When I checked it with the volt meter it showed about +5 volts on it when the other meter lead was on ground. The voltage toggled as I turned the channel selector. Why would a PLL ground pin show voltage? The second red flag was when the lowest four programming pins kept counting up to 9 (1001) and then resetting to all zeros (0000) as I turned the channel selector. Straight binary does not do that, but BCD does. Night Ranger I've been looking around for any data I can find, and what I've stumbled across so far all lists pin 16 as the Gnd pin. Programmable divider pins are 8 through 15, and are supposed to be straight binary. The biggest shortcoming of this PLL was that it did not work at higher frequencies, and I believe the reference was probably 5.12 Mhz instead of the typical 10.24 Mhz. So I'm at a loss to explain what you've been seeing. BCD programming? Yea if it was a uPD-858. But his is just weird. What happens if you try to load a number greater than 9 (1001)? Where does that take you?
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on May 19, 2015 21:09:47 GMT -5
I can add that your Kraco radio was definitely making the trip up to S.E. PA today. Heard you Night Ranger sporadically in my mud-duck-pick-up-truck for the first half hour, then via a BIG SIGNAL around 3:30 PM. Who says roger beeps aren't good for anything I know 44 Dave (on his base) and Sandbagger (in his mobile) may have heard you also. Certainly hope to hear more quality propagation from the Carol inaPirate in the coming weeks! Sparky 775 out. I was in the "Mud duck" (4 watt) mobile, and I tried calling, but I didn't think I would make it with my TRC-465 and a stock mic...... One of these days I'll get the amp installed....
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Post by Night Ranger on May 19, 2015 22:10:10 GMT -5
The first give away that something was wrong with online documentation was pin 16 is suppose to be Vss or ground. When I checked it with the volt meter it showed about +5 volts on it when the other meter lead was on ground. The voltage toggled as I turned the channel selector. Why would a PLL ground pin show voltage? The second red flag was when the lowest four programming pins kept counting up to 9 (1001) and then resetting to all zeros (0000) as I turned the channel selector. Straight binary does not do that, but BCD does. Night Ranger I've been looking around for any data I can find, and what I've stumbled across so far all lists pin 16 as the Gnd pin. Programmable divider pins are 8 through 15, and are supposed to be straight binary. The biggest shortcoming of this PLL was that it did not work at higher frequencies, and I believe the reference was probably 5.12 Mhz instead of the typical 10.24 Mhz. So I'm at a loss to explain what you've been seeing. BCD programming? Yea if it was a uPD-858. But his is just weird. What happens if you try to load a number greater than 9 (1001)? Where does that take you? I looked up the Kraco KCB-2010a in my Sams Photofact collection (CB-106) and the schematic definitely shows pin 16 on the PLL01a being cycled as the lowest power programming pin. That confirms the online data pin outs for the PLL01a are wrong. : ) Night Ranger
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on May 20, 2015 6:12:17 GMT -5
I've been looking around for any data I can find, and what I've stumbled across so far all lists pin 16 as the Gnd pin. Programmable divider pins are 8 through 15, and are supposed to be straight binary. The biggest shortcoming of this PLL was that it did not work at higher frequencies, and I believe the reference was probably 5.12 Mhz instead of the typical 10.24 Mhz. So I'm at a loss to explain what you've been seeing. BCD programming? Yea if it was a uPD-858. But his is just weird. What happens if you try to load a number greater than 9 (1001)? Where does that take you? I looked up the Kraco KCB-2010a in my Sams Photofact collection (CB-106) and the schematic definitely shows pin 16 on the PLL01a being cycled as the lowest power programming pin. That confirms the online data pin outs for the PLL01a are wrong. : ) Night Ranger Ok, then here's the obvious follow-up question, which pin IS connected to gnd?
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Post by Night Ranger on May 20, 2015 6:17:06 GMT -5
Pin 8 is connected to ground on the Sams Photofact. The N codes for CB channels 1 through 23 look like this. Notice the four right most bits reset after reaching binary 9 (1001). The first four (left most) binary digits can't be BCD because they go to decimal 10 ( binary 1010) from channel 17 up. See the link below. Grumpy's was removing the tabs for formatting. www.shadowstorm.com/cb/scripts/pll01a-kcb-2010a.txtNight Ranger
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Post by Night Ranger on May 20, 2015 8:08:12 GMT -5
Pin 8 is connected to ground on the Sams Photofact. The N codes for CB channels 1 through 23 look like this. Notice the four right most bits reset after reaching binary 9 (1001). The first four (left most) binary digits can't be BCD because they go to decimal 10 ( binary 1010) from channel 17 up. See the link below. Grumpy's was removing the tabs for formatting. www.shadowstorm.com/cb/scripts/pll01a-kcb-2010a.txtNight Ranger I mapped out the PLL01a from Sams Photofact CB-106 for the Kraco KCB-2310a. This is the correct pin out. The other online resources and the "CB PLL Databook" are wrong. Correct PLL01a pinouts; Pin 1 = Vdd - 5.37 volts in Pin 2 = Fin = Frequency input to the programmable divider ( 2.xxx MHz down mix signal after 21 MHz VCO is mixed with doubled 9.510 Mhz crystal oscillator) Pin 3 = Ref In - Reference frequency oscillator (6.4 MHz) Pin 4 = NC - No connection, but probably unused frequency select (FS) for 5 kHz channel steps. Pin 5 = Phase Detect output voltage to drive the VCO up or down Pin 6 = PD In - Phase Detect frequency input from the programmable divider Pin 7 = PD Output - Output from the Programmable Divider which is then tied back in to "Phase Detect in" on pin 6 Pin 8 = Vss - ground pin Pin 9 = P7 - programming pin pin 10 = P6 - programming pin pin 11 = P5 - programming pin pin 12 = P4 - programming pin pin 13 = P3 - programming pin pin 14 = P2 - programming pin pin 15 = P1 - programming pin pin 16 = P0 - programming pin Pin 10 is listed as NC (no connection) since it's value is always zero for channels 1 through 23. The 1st IF frequency is 5.945 MHz. Second IF is 455 kHz. The first IF is mixed with a sample from the 6.4 MHz PLL reference oscillator to give the second IF of 455 kHz. Night Ranger
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Post by Night Ranger on May 20, 2015 9:26:18 GMT -5
Pin 8 is connected to ground on the Sams Photofact. The N codes for CB channels 1 through 23 look like this. Notice the four right most bits reset after reaching binary 9 (1001). The first four (left most) binary digits can't be BCD because they go to decimal 10 ( binary 1010) from channel 17 up. See the link below. Grumpy's was removing the tabs for formatting. www.shadowstorm.com/cb/scripts/pll01a-kcb-2010a.txtNight Ranger I mapped out the PLL01a from Sams Photofact CB-106 for the Kraco KCB-2310a. This is the correct pin out. The other online resources and the "CB PLL Databook" are wrong. Correct PLL01a pinouts; Pin 1 = Vdd - 5.37 volts in Pin 2 = Fin = Frequency input to the programmable divider ( 2.xxx MHz down mix signal after 21 MHz VCO is mixed with doubled 9.510 Mhz crystal oscillator) Pin 3 = Ref In - Reference frequency oscillator (6.4 MHz) Pin 4 = NC - No connection, but probably unused frequency select (FS) for 5 kHz channel steps. Pin 5 = Phase Detect output voltage to drive the VCO up or down Pin 6 = PD In - Phase Detect frequency input from the programmable divider Pin 7 = PD Output - Output from the Programmable Divider which is then tied back in to "Phase Detect in" on pin 6 Pin 8 = Vss - ground pin Pin 9 = P7 - programming pin pin 10 = P6 - programming pin pin 11 = P5 - programming pin pin 12 = P4 - programming pin pin 13 = P3 - programming pin pin 14 = P2 - programming pin pin 15 = P1 - programming pin pin 16 = P0 - programming pin Pin 10 is listed as NC (no connection) since it's value is always zero for channels 1 through 23. The 1st IF frequency is 5.945 MHz. Second IF is 455 kHz. The first IF is mixed with a sample from the 6.4 MHz PLL reference oscillator to give the second IF of 455 kHz. Night Ranger I forgot to add one thing. To determine the programming needed to reach the desired frequency take the frequency you want and subtract 24.965 MHz to determine the needed VCO down mix frequency. For example to reach 26.965 MHz subtract 24.965 which equals 2.00 MHz. Now program pins 9 through 16 as follows; "10" for 2 MHz (pins 9 and 10) "00" for the 100 KHz value (pins 11 and 12) "0000" for the 10 kHz value. (pins 13,14,15, and 16) 10 00 0000 To reach 27.305 MHz (channel 30) subtract 24.965 which equals 2.340 MHz; Now program pins 9 through 16 as follows; "10" for 2 MHz (pins 9 and 10) "11" for 300 MHz (pins 11 and 12) "0100" for 40 kHz (pins 13,14,15,16) 10 11 0100 It looks like you can't program frequencies higher than "27.355 MHz" as that would require a "4" in the second two bit value, and the highest possible value available is decimal 3 or "11" in binary. At some point the VCO lost lock and resonated around 27.5xx MHz, but I don't remember what programming I forced on the chip at that time.* *Hmm...Then again the first binary pair could be programmed to "11" which would be 3.xx MHz (11 00 0000), but I don't know if the VCO would travel that far. 24.965 MHz plus 3.000 MHz equals "27.965 MHz". Night Ranger
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Post by Night Ranger on May 20, 2015 12:18:08 GMT -5
In the words of Rosanne Rosannadanna; "It just goes to show..It's always something!" GILDA RADNER - 1980 - Comedy Routine www.youtube.com/watch?v=OlQ9iOir6j8Well I decided to cross reference Sam's Photofacts with other radios that use the PLL01a. Sams Photofact's CB-106 (Kraco KCB-2010a) and Sam's Photofact CB-152 (Kraco KCB-2320a) both show the PLL01a as I specified although Sams CB-152 does not show the individual contacts for the channel selector switch. ..however.... Sams Photofact CB-137 (Hy-Gain Hy-Range I and II - 681 and 682) show the PLL01a with slightly different loop mixing and reference frequencies and pin 8 used as a programming pin and pin 16 grounded. The only difference in pin out is the reversal of pin 8 and pin 16. Go figure. Unfortunately I don't have the Hy-Gain 681 and 682 pll01a version radios to play with. >: 0 Night Ranger
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Post by Night Ranger on May 20, 2015 22:16:38 GMT -5
Well a little more prodding provided something new. Apparently pins 10, 11, and 12 specify the 100kHz digit, because when pins 9 and 10 are set and pins 11 though 16 are all zeros the VCO down mix frequency jumps to 2.400 MHz. Adding pin 12 makes the VCO go to 2.500 MHz.
So.. 2.400 MHz VCO down mix frequency 1 100 0000 equals 2.400 MHz 1 100 0001 equals 2.401 MHz
..and..
1 101 0000 equals 2.500 MHz 1 101 0001 equals 2.501 MHz
Now I wonder what happens if I make pin 16 Dss and use pin 8 as the highest power as is used in the Hygain 681 and 682 models?
Night Ranger
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Sandbagger
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Post by Sandbagger on May 21, 2015 6:04:36 GMT -5
Well a little more prodding provided something new. Apparently pins 10, 11, and 12 specify the 100kHz digit, because when pins 9 and 10 are set and pins 11 though 16 are all zeros the VCO down mix frequency jumps to 2.400 MHz. Adding pin 12 makes the VCO go to 2.500 MHz. So.. 2.400 MHz VCO down mix frequency 1 100 0000 equals 2.400 MHz 1 100 0001 equals 2.401 MHz ..and.. 1 101 0000 equals 2.500 MHz 1 101 0001 equals 2.501 MHz Now I wonder what happens if I make pin 16 Dss and use pin 8 as the highest power as is used in the Hygain 681 and 682 models? Night Ranger Interesting.... You're saying that there are other radios out there that do use pin 16 as ground? I don't know how you could NOT use the designated ground pin in a fashion like what you seem to have in your Kraco. This whole thing makes my head spin, as it's completely different from what the information I have states. But I wonder how it would affect the operation of the chip to utilize what is supposed to be the ground pin as a programming pin? It might explain the strange truth table, but unless there's an undocumented feature where it switches between BCD and Binary programming depending on whether you ground pin 8 or 16, it seems like a stretch.
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Sandbagger
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Post by Sandbagger on May 21, 2015 6:06:58 GMT -5
In the words of Rosanne Rosannadanna; "It just goes to show..It's always something!" GILDA RADNER - 1980 - Comedy Routine www.youtube.com/watch?v=OlQ9iOir6j8Well I decided to cross reference Sam's Photofacts with other radios that use the PLL01a. Sams Photofact's CB-106 (Kraco KCB-2010a) and Sam's Photofact CB-152 (Kraco KCB-2320a) both show the PLL01a as I specified although Sams CB-152 does not show the individual contacts for the channel selector switch. ..however.... Sams Photofact CB-137 (Hy-Gain Hy-Range I and II - 681 and 682) show the PLL01a with slightly different loop mixing and reference frequencies and pin 8 used as a programming pin and pin 16 grounded. The only difference in pin out is the reversal of pin 8 and pin 16. Go figure. Unfortunately I don't have the Hy-Gain 681 and 682 pll01a version radios to play with. >: 0 Night Ranger ......and the plot thickens.........
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Post by Night Ranger on May 21, 2015 8:16:48 GMT -5
In the words of Rosanne Rosannadanna; "It just goes to show..It's always something!" GILDA RADNER - 1980 - Comedy Routine www.youtube.com/watch?v=OlQ9iOir6j8Well I decided to cross reference Sam's Photofacts with other radios that use the PLL01a. Sams Photofact's CB-106 (Kraco KCB-2010a) and Sam's Photofact CB-152 (Kraco KCB-2320a) both show the PLL01a as I specified although Sams CB-152 does not show the individual contacts for the channel selector switch. ..however.... Sams Photofact CB-137 (Hy-Gain Hy-Range I and II - 681 and 682) show the PLL01a with slightly different loop mixing and reference frequencies and pin 8 used as a programming pin and pin 16 grounded. The only difference in pin out is the reversal of pin 8 and pin 16. Go figure. Unfortunately I don't have the Hy-Gain 681 and 682 pll01a version radios to play with. >: 0 Night Ranger ......and the plot thickens......... Now I'm starting to think there is more than one version of the Hy-Gain Hy-Range 681/682, because CBTricks.com shows the PLL01a with pin 8 grounded and pin 16 used as a programming pin. Hy-Gain 682 schematic www.cbtricks.com/radios/hygain/hygain_681_682_683/graphics/hygain_682_sm_sch.jpgI wonder if the engineers at Cybernet started getting pissed off at management for making them come up with some many versions of the Cybernet 23 channel chassis. 1) 12 crystals crystal synthesis version 2) pll01a version 1 3) pll01a version 2 4) pll02a three crystal version 5) pll02a two crystal version ..and then came the 40 channel pll02a two crystal version. Night Ranger
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Sandbagger
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Post by Sandbagger on May 21, 2015 12:38:36 GMT -5
......and the plot thickens......... Now I'm starting to think there is more than one version of the Hy-Gain Hy-Range 681/682, because CBTricks.com shows the PLL01a with pin 8 grounded and pin 16 used as a programming pin. Hy-Gain 682 schematic www.cbtricks.com/radios/hygain/hygain_681_682_683/graphics/hygain_682_sm_sch.jpgI wonder if the engineers at Cybernet started getting pissed off at management for making them come up with some many versions of the Cybernet 23 channel chassis. 1) 12 crystals crystal synthesis version 2) pll01a version 1 3) pll01a version 2 4) pll02a three crystal version 5) pll02a two crystal version ..and then came the 40 channel pll02a two crystal version. Night Ranger The interesting thing is that not all versions of the Cybernet chassis made it into production across all product lines that used that particular board set. For instance, the Midland "882" series radio went from the 13-882B, the 12 channel crystal version, to the 13-882C 23 channel PLL-02a 3 crystal version, to the 77-882 40 channel PLL-02a 2 crystal version. I'm pretty sure the transition from the '02a 3 crystal version to the 2 crystal version occurred during the 40 channel radio roll-out in 1977. There were a few factory refurbed 23 channel 3 crystal versions that had a 40 channel switch (which because of the different truth table, was different than the 2 crystal version switch) installed and the respective radio repackaged as a 40 channel. I believe Hy-Gain did this more so than others. It would also appear that Hy-Gain indulged more of Cybernet's intermediate versions as well. It was an interesting time for many of the Japanese CB chassis makers when they were designing their first PLL chassis. Uniden went through similar evolutions as well, as did NDI, and I'm sure others.
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Post by Night Ranger on May 21, 2015 13:22:57 GMT -5
Now I'm starting to think there is more than one version of the Hy-Gain Hy-Range 681/682, because CBTricks.com shows the PLL01a with pin 8 grounded and pin 16 used as a programming pin. Hy-Gain 682 schematic www.cbtricks.com/radios/hygain/hygain_681_682_683/graphics/hygain_682_sm_sch.jpgI wonder if the engineers at Cybernet started getting pissed off at management for making them come up with some many versions of the Cybernet 23 channel chassis. 1) 12 crystals crystal synthesis version 2) pll01a version 1 3) pll01a version 2 4) pll02a three crystal version 5) pll02a two crystal version ..and then came the 40 channel pll02a two crystal version. Night Ranger The interesting thing is that not all versions of the Cybernet chassis made it into production across all product lines that used that particular board set. For instance, the Midland "882" series radio went from the 13-882B, the 12 channel crystal version, to the 13-882C 23 channel PLL-02a 3 crystal version, to the 77-882 40 channel PLL-02a 2 crystal version. I'm pretty sure the transition from the '02a 3 crystal version to the 2 crystal version occurred during the 40 channel radio roll-out in 1977. There were a few factory refurbed 23 channel 3 crystal versions that had a 40 channel switch (which because of the different truth table, was different than the 2 crystal version switch) installed and the respective radio repackaged as a 40 channel. I believe Hy-Gain did this more so than others. It would also appear that Hy-Gain indulged more of Cybernet's intermediate versions as well. It was an interesting time for many of the Japanese CB chassis makers when they were designing their first PLL chassis. Uniden went through similar evolutions as well, as did NDI, and I'm sure others. I imagine it had to do with how big an order each brand name purchased from Cybernet versus their sales volume. Small production orders placed frequently over the 1975 to 1977 time period would have made for more versions in that name brand's product line versus a big order in 1975 and another big order in 1977 for a different brand name. It looks like the Kraco KCB-2310a, KCB-2320a, and KCB-2330a are the PLL01a version I am working with. Kraco KCB-2310, KCB-2320, and KCB-2330 are 12 crystal crystal synthesis, and KCB-2310b, KCB-2320b, and KCB-2330b are three crystal pll02a. Kraco KCB-4010, KCB-4020, and KCB-4030 are 40 channel two crystal PLL02a versions. Night Ranger
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Post by Night Ranger on May 24, 2015 8:42:01 GMT -5
I played with forcing pins 11 and 10 high with 5+ volts taken from Vdd (pin 1). Below are the results;
Pin 11 forced high Ch Select => New channel 1 => 17 2 => 18 3 => 19 4 => 20 5 => 21 6 => 22 7 => 24 8 => 23 9 => 26 10 => 27 11 => 28 12 => 30 13 => 31 14 => 32 15 => 33 16 => 35 17 - 23 = Normal
Pin 10 forced high 1 => 36 2 => 37 3 => 38 4 => 40 5 => 41 6 => 42 7 => 43 8 => 45 9 => 46 10 => 47 11 => 48 12 => 50 13 => 51 14 => 52 15 => 53 16+ = VCO becomes unlocked
The VCO is "wobbly" on the last few highest channels and changes frequency slightly with modulation.
Removing voltage from PIN 9 should allow channels below 1, but I have not played with that yet.
Night Ranger
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on May 25, 2015 15:22:59 GMT -5
I played with forcing pins 11 and 10 high with 5+ volts taken from Vdd (pin 1). Below are the results; Pin 11 forced high Ch Select => New channel 1 => 17 2 => 18 3 => 19 4 => 20 5 => 21 6 => 22 7 => 24 8 => 23 9 => 26 10 => 27 11 => 28 12 => 30 13 => 31 14 => 32 15 => 33 16 => 35 17 - 23 = Normal Pin 10 forced high 1 => 36 2 => 37 3 => 38 4 => 40 5 => 41 6 => 42 7 => 43 8 => 45 9 => 46 10 => 47 11 => 48 12 => 50 13 => 51 14 => 52 15 => 53 16+ = VCO becomes unlocked The VCO is "wobbly" on the last few highest channels and changes frequency slightly with modulation. Removing voltage from PIN 9 should allow channels below 1, but I have not played with that yet. Night Ranger If I had that radio back in 1976, when I was first curious about this "newfangled" PLL technology, I'd have been like a kid in a candy store, with range like that..... You can correct the "wobbly" VCO with a quick 1/8 turn of the VCO coil. Of course you trade off lower range for the upper range. But it's cool o experiment just to see where you can put the radio.
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Post by Night Ranger on May 25, 2015 15:55:59 GMT -5
I played with forcing pins 11 and 10 high with 5+ volts taken from Vdd (pin 1). Below are the results; Pin 11 forced high Ch Select => New channel 1 => 17 2 => 18 3 => 19 4 => 20 5 => 21 6 => 22 7 => 24 8 => 23 9 => 26 10 => 27 11 => 28 12 => 30 13 => 31 14 => 32 15 => 33 16 => 35 17 - 23 = Normal Pin 10 forced high 1 => 36 2 => 37 3 => 38 4 => 40 5 => 41 6 => 42 7 => 43 8 => 45 9 => 46 10 => 47 11 => 48 12 => 50 13 => 51 14 => 52 15 => 53 16+ = VCO becomes unlocked The VCO is "wobbly" on the last few highest channels and changes frequency slightly with modulation. Removing voltage from PIN 9 should allow channels below 1, but I have not played with that yet. Night Ranger If I had that radio back in 1976, when I was first curious about this "newfangled" PLL technology, I'd have been like a kid in a candy store, with range like that..... You can correct the "wobbly" VCO with a quick 1/8 turn of the VCO coil. Of course you trade off lower range for the upper range. But it's cool o experiment just to see where you can put the radio. I already tried that (T-101). It is already maxed at the high end. The VCO is stable from about channel 45 down, and the modulation induced "wobble" gets worse as it nears the end of it's range. I am treating this project from the perspective of being a young kid with no money, and I have to use what I have available. I stole the bigger signal/RF meter out of a junked Kraco KCB-2330 (crystal synthesis) parts radio and "super glued" the bigger meter to the side of the little Kraco KCB-2310a just for laughs. I also back lit it with two 6 volt lamps in series powered from a 12 volt trace on the Kraco PC board. I stole those two lamps from the Kraco KCB-2330 parts radio as well. This is my laughable Kraco Frankenstein radio so far. I'll probably make a better looking encasement for the external meter from thick black construction paper. Kraco Frankenstein CB Radio www.shadowstorm.com/cb/images/Kraco-Frankenstein-CB.jpgNext I plan to swipe the 455 kHz ceramic filter out of the parts KCB-2330 and possibly a junked Midland 13-882b and chain them together with the stock 455 kHz ceramic filter to increase the channel selectivity. I also plan on building a little peamp stage to compensate for the signal loss of the additional ceramic filters. Then comes cutting the trace on pin 9 to force that pin low and get the extra channels below channel 1. After that I may widen the bass frequency response of the mic amp circuit by changing out the .01 uf coupling capacitor on the input side of the TA7205p audio amp. For the moment I am using my Astron power supply to run it, but to make it true to life I will have to build a 12 volt regulated power supply from parts to run it as well. I realigned the transmit section for channel 20 and it is showing 4 watts from 1 to 40. The receive sensitivity trails off as expected after the radio goes above 40. : ) Night Ranger
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Post by Night Ranger on May 26, 2015 8:44:11 GMT -5
Well I tried removing the 5+ volts from pin 9 and no combination of programming pins would result in VCO lock. Apparently the PLL01a in this mode requires the 5+ volts on pin 9. However it should still be possible to get channels below 1 by switching out the 9.510 MHz VCO down mix loop mixing crystal with a 9.360 MHz loop mixing crystal. The end result would be channel 23 would become 26.955 MHz and lower channels would proceed downward with the expected skips and out of sequence frequencies for the RC channels and channels 22 and 23.
For example, on channel 23 the PLL01a is expecting to see a down mix signal of 2.290 MHz. With the VCO running at 21.010 MHz and the doubled loop mix signal of 18.720 MHz the down mix signal would still be the expected 2.290 MHz => 21.010 - (9.360 * 2) = 2.290 MHz. 5.945 MHz (the 1st IF) + 21.010 = 26.955 MHz. The VCO will lose lock at some point as it nears the bottom of it's range, but I don't know what that is.
That still leaves the possibility of using pin 8 as a programming pin and and grounding pin 16. If the PLL01a can then be programming in direct binary instead of the odd ball (bin or BCD?)/ BCD of this mode then other possibilities may exist.
Night Ranger
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Post by Night Ranger on May 26, 2015 11:21:41 GMT -5
Well I tried removing the 5+ volts from pin 9 and no combination of programming pins would result in VCO lock. Apparently the PLL01a in this mode requires the 5+ volts on pin 9. However it should still be possible to get channels below 1 by switching out the 9.510 MHz VCO down mix loop mixing crystal with a 9.360 MHz loop mixing crystal. The end result would be channel 23 would become 26.955 MHz and lower channels would proceed downward with the expected skips and out of sequence frequencies for the RC channels and channels 22 and 23. For example, on channel 23 the PLL01a is expecting to see a down mix signal of 2.290 MHz. With the VCO running at 21.010 MHz and the doubled loop mix signal of 18.720 MHz the down mix signal would still be the expected 2.290 MHz => 21.010 - (9.360 * 2) = 2.290 MHz. 5.945 MHz (the 1st IF) + 21.010 = 26.955 MHz. The VCO will lose lock at some point as it nears the bottom of it's range, but I don't know what that is. That still leaves the possibility of using pin 8 as a programming pin and and grounding pin 16. If the PLL01a can then be programming in direct binary instead of the odd ball (bin or BCD?)/ BCD of this mode then other possibilities may exist. Night Ranger ..Oh yea...And lets not forget that FS (Frequency Select) pin (pin 4) which is disconnected. I'll try that first, and then comes the brain bender.... Switching the PLL01a to straight binary mode which means the programming pins shift over by one AND the pin powers reverse. At least that is what the PLL01a "CB PLL Data Book" says. ; ) Night Ranger
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on May 27, 2015 6:32:33 GMT -5
Well I tried removing the 5+ volts from pin 9 and no combination of programming pins would result in VCO lock. Apparently the PLL01a in this mode requires the 5+ volts on pin 9. However it should still be possible to get channels below 1 by switching out the 9.510 MHz VCO down mix loop mixing crystal with a 9.360 MHz loop mixing crystal. The end result would be channel 23 would become 26.955 MHz and lower channels would proceed downward with the expected skips and out of sequence frequencies for the RC channels and channels 22 and 23. For example, on channel 23 the PLL01a is expecting to see a down mix signal of 2.290 MHz. With the VCO running at 21.010 MHz and the doubled loop mix signal of 18.720 MHz the down mix signal would still be the expected 2.290 MHz => 21.010 - (9.360 * 2) = 2.290 MHz. 5.945 MHz (the 1st IF) + 21.010 = 26.955 MHz. The VCO will lose lock at some point as it nears the bottom of it's range, but I don't know what that is. That still leaves the possibility of using pin 8 as a programming pin and and grounding pin 16. If the PLL01a can then be programming in direct binary instead of the odd ball (bin or BCD?)/ BCD of this mode then other possibilities may exist. Night Ranger ..Oh yea...And lets not forget that FS (Frequency Select) pin (pin 4) which is disconnected. I'll try that first, and then comes the brain bender.... Switching the PLL01a to straight binary mode which means the programming pins shift over by one AND the pin powers reverse. At least that is what the PLL01a "CB PLL Data Book" says. ; ) Night Ranger I don't remember the PLL 01 or 02 having a "mode select" pin, like the uPD-861 had, where it switches between a straight binary and some other mode. If I remember correctly, the "FS" pin switched between 10 Khz and 5 Khz steps.
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Post by Night Ranger on May 27, 2015 8:04:55 GMT -5
..Oh yea...And lets not forget that FS (Frequency Select) pin (pin 4) which is disconnected. I'll try that first, and then comes the brain bender.... Switching the PLL01a to straight binary mode which means the programming pins shift over by one AND the pin powers reverse. At least that is what the PLL01a "CB PLL Data Book" says. ; ) Night Ranger I don't remember the PLL 01 or 02 having a "mode select" pin, like the uPD-861 had, where it switches between a straight binary and some other mode. If I remember correctly, the "FS" pin switched between 10 Khz and 5 Khz steps. #### UPDATE: I edited this post as I made an error the first time around. #### That is what I was referring to with the FS pin 4 (5 kHz vs 10 kHz steps). If there is a mode select on the pll01a it appears to be done with pin 9 high and pin 8 as Vss (GND). In BCD mode pin 16 is programming pin P0 and pin 10 is programming pin P7. Pins 16,15,14,and 13 are programmed in BCD. Pins 12,11,and 10 could be either binary or BCD since we really need another "bit" to tell the difference. Kraco KCB-2310a truth shows shows BCD programming on the four lowest bits (right most). http//www.shadowstorm.com/cb/scripts/pll01a-kcb-2010a.txt So in BCD mode the programming pins are pins 10 through 16 (P7 ... P0), but if the pll01a data in the "CB PLL Data Book" and on the Internet is correct then switching pin 16 to (VSS) ground should enable pins 8 through 15 as binary programming pins with pin 8 becoming programming pin "P7" and pin 15 becoming programming pin "P0" The Hy-Gain model previously mentioned is shown in the binary mode in Sams Photofact CB-137 (Hy-Gain Hy-Range I and II - 681 and 682). There are apparently Hy-Gain Hy-Range 681,681a models and 682,682a models, but I don't know which one is BCD and which one is binary yet. >>> Dang that is confusing! I had to re-write this post more than once! <<< Here is the current status of experiments with the Kraco KCB-2310a 1) I chained two Murata CFU455 H3 ceramic filters together in the 455 kHz IF using a separate perf board. I used the one that came with the Kraco plus one from a junked Kraco KCB-2330. The selectivity has noticeably improved. 2) I realigned the receiver to center on 27.255 MHz to make the receiver sensitivity more even across the original 23 channels plus the added range above 23. 3) Setting pin 4 high resulted in nothing usable with the stock channel selector programming even with pins 10 and 11 forced high. Things to do; 1) Add the "A" channels and skipped channels 25,29,34,39,44,49,and 54 via programming pin 16. Some "A" channels need pin 16 forced high and some "A" channels need pin 16 forced low. 2) Decide whether to abandon BCD mode and go binary (if the CB PLL Data Book is correct) OR use switchable loop mixing crystals to get below channel 1. Channels above 40 are mostly freeband sideband, but there is some AM activity below 1. Not that I am that big on transmitting below 1, but at least I could listen with this radio. 3) Try a different varactor diode to see if I can extend the VCO range up past channel 27.535 MHz. 4) Update my KCB-2310a pll01a truth chart to include channels above 23. Night Ranger
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Post by Night Ranger on May 27, 2015 14:04:29 GMT -5
I updated my previous post as I got confused without the schematics in front of me. Please re-read previous post. Night Ranger
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Sandbagger
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Post by Sandbagger on May 27, 2015 17:15:26 GMT -5
I don't remember the PLL 01 or 02 having a "mode select" pin, like the uPD-861 had, where it switches between a straight binary and some other mode. If I remember correctly, the "FS" pin switched between 10 Khz and 5 Khz steps. #### UPDATE: I edited this post as I made an error the first time around. #### That is what I was referring to with the FS pin 4 (5 kHz vs 10 kHz steps). If there is a mode select on the pll01a it appears to be done with pin 9 high and pin 8 as Vss (GND). In BCD mode pin 16 is programming pin P0 and pin 10 is programming pin P7. Pins 16,15,14,and 13 are programmed in BCD. Pins 12,11,and 10 could be either binary or BCD since we really need another "bit" to tell the difference. Kraco KCB-2310a truth shows shows BCD programming on the four lowest bits (right most). http//www.shadowstorm.com/cb/scripts/pll01a-kcb-2010a.txt So in BCD mode the programming pins are pins 10 through 16 (P7 ... P0), but if the pll01a data in the "CB PLL Data Book" and on the Internet is correct then switching pin 16 to (VSS) ground should enable pins 8 through 15 as binary programming pins with pin 8 becoming programming pin "P7" and pin 15 becoming programming pin "P0" The Hy-Gain model previously mentioned is shown in the binary mode in Sams Photofact CB-137 (Hy-Gain Hy-Range I and II - 681 and 682). There are apparently Hy-Gain Hy-Range 681,681a models and 682,682a models, but I don't know which one is BCD and which one is binary yet. >>> Dang that is confusing! I had to re-write this post more than once! <<< Here is the current status of experiments with the Kraco KCB-2310a 1) I chained two Murata CFU455 H3 ceramic filters together in the 455 kHz IF using a separate perf board. I used the one that came with the Kraco plus one from a junked Kraco KCB-2330. The selectivity has noticeably improved. 2) I realigned the receiver to center on 27.255 MHz to make the receiver sensitivity more even across the original 23 channels plus the added range above 23. 3) Setting pin 4 high resulted in nothing usable with the stock channel selector programming even with pins 10 and 11 forced high. Things to do; 1) Add the "A" channels and skipped channels 25,29,34,39,44,49,and 54 via programming pin 16. Some "A" channels need pin 16 forced high and some "A" channels need pin 16 forced low. 2) Decide whether to abandon BCD mode and go binary (if the CB PLL Data Book is correct) OR use switchable loop mixing crystals to get below channel 1. Channels above 40 are mostly freeband sideband, but there is some AM activity below 1. Not that I am that big on transmitting below 1, but at least I could listen with this radio. 3) Try a different varactor diode to see if I can extend the VCO range up past channel 27.535 MHz. 4) Update my KCB-2310a pll01a truth chart to include channels above 23. You can gain additional VCO range by simply paralleling a second identical (or close) varactor diode with the original in circuit and retuning the coil. I had my AM 02a Cybernet chassis radios going up well into 10 meters after doing that. The problem then becomes one of the TX and RX stage tuning being not wide enough to cover the VCO range with good TX power and RX sensitivity. I played around with increasing interstage coupling cap values and other tricks and managed to get a slight increase in bandwidth. But in the end it's not really worth the trouble except in an experimental sense to satisfy curiosity.
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Post by Night Ranger on May 27, 2015 17:49:25 GMT -5
You can gain additional VCO range by simply paralleling a second identical (or close) varactor diode with the original in circuit and retuning the coil. I had my AM 02a Cybernet chassis radios going up well into 10 meters after doing that. The problem then becomes one of the TX and RX stage tuning being not wide enough to cover the VCO range with good TX power and RX sensitivity. I played around with increasing interstage coupling cap values and other tricks and managed to get a slight increase in bandwidth. But in the end it's not really worth the trouble except in an experimental sense to satisfy curiosity. Satisfying my nostalgic curiosity is more of what this is about. Since I lacked technical understanding back in the 1970s I could not have done then what I am doing now. This is an intellectual exercise in what I could have done back then if I had the knowledge I have now. My original Midland 13-853 23 channel radio from 1976 used the 12 crystal crystal synthesis scheme, so the only possible extra channel was channel 22a/24 without adding more crystals. I did discover that back then. My parents Morse CB-2000 in the family station wagon was a real pain to use on the base due to the really bad selectivity, and it used the 14 crystal scheme. The Midland 79-892 I purchased in 1979 with money from my first real job had real possibilities though with it's 40 channel sideband pll02a Cybernet chassis. My friend Red Horse destroyed a number of CB's. If I had been tech savvy back then I could have gotten my hands on a number of his disasters. The first DOA CB from him was a 23 channel Sears with the UPD861 PLL. The second destroyed CB was a 40 channel Sears Roadtalker, but I don't know which PLL chip was in that one. I did get the 40 channel Royce 609 he KO'd for $25.00, and I repaired it. It is PLL, but I don't know which one. Those sound like future projects. Actually I probably would have repaired Red Horse's first CB radio and given it back to him since I enjoyed having him on the air with me. Knowing Red Horse I probably would have had to repair it more than once before it finally wound up in my parts bin. Night Ranger
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Post by Night Ranger on May 28, 2015 10:07:07 GMT -5
You can gain additional VCO range by simply paralleling a second identical (or close) varactor diode with the original in circuit and retuning the coil. I had my AM 02a Cybernet chassis radios going up well into 10 meters after doing that. The problem then becomes one of the TX and RX stage tuning being not wide enough to cover the VCO range with good TX power and RX sensitivity. I played around with increasing interstage coupling cap values and other tricks and managed to get a slight increase in bandwidth. But in the end it's not really worth the trouble except in an experimental sense to satisfy curiosity. I found out why the VCO becomes wobbly at it's top range and then loses lock around 27.54x MHz. The voltage output from the programmable divider is maxed out and stops increasing after 27.54x MHz. The voltage in on Vdd (pin 1 ) is 5.36 volts and the max voltage from the "PD out" (pin 5) at 27.54x MHz is 5.35 volts. It's out of juice! That also explains why adjusting the VCO coil did not fix it. Night Ranger
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on May 28, 2015 10:27:46 GMT -5
You can gain additional VCO range by simply paralleling a second identical (or close) varactor diode with the original in circuit and retuning the coil. I had my AM 02a Cybernet chassis radios going up well into 10 meters after doing that. The problem then becomes one of the TX and RX stage tuning being not wide enough to cover the VCO range with good TX power and RX sensitivity. I played around with increasing interstage coupling cap values and other tricks and managed to get a slight increase in bandwidth. But in the end it's not really worth the trouble except in an experimental sense to satisfy curiosity. I found out why the VCO becomes wobbly at it's top range and then loses lock around 27.54x MHz. The voltage output from the programmable divider is maxed out and stops increasing after 27.54x MHz. The voltage in on Vdd (pin 1 ) is 5.36 volts and the max voltage from the "PD out" (pin 5) at 27.54x MHz is 5.35 volts. It's out of juice! That also explains why adjusting the VCO coil did not fix it. Night Ranger Adjusting the coil SHOULD fix it, as that is what you are compensating for. The VCO has a voltage range between about .5V to about 5V give or take. The voltage is dependent on the frequency of the oscillator, which is set by the LC values of the varactor diode and the tank coil. Move the coil value, and the VCO voltage moves the capacitance of the varactor to maintain frequency. Likewise, if you are hitting the edges of the VCO voltage ranges (either high or low), you can move the coil value to shift the VCO back into the usable range. Try it. Put your volt meter on the VCO voltage on one of your higher channels, and then adjust the coil and the voltage should swing up or down depending on which way you turn it. You should probably be turning it counterclockwise to decrease the inductance, which should shift frequency higher. If you can no longer compensate the frequency, then you've probably ran out of adjustment. I've never had that problem with the later 02a boards, but I can't comment on the 01's
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