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Post by bioman on Jun 27, 2008 10:17:22 GMT -5
well i flat out LOVE the courier i got from sandbagger but i wish it would go up to 40so i can use it on 36USB and 38LSB where i mainly talk
anybody know which VFO i will need for this??
of is it possible to modify the PLL to go up there??
i pulled a powered D-104 off of another rig and now it out-talks everything else in my shack
scott
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Post by bioman on Jun 27, 2008 10:52:47 GMT -5
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Sandbagger
Administrator/The Boss 
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Post by Sandbagger on Jun 27, 2008 11:44:36 GMT -5
well i flat out LOVE the courier i got from sandbagger but i wish it would go up to 40so i can use it on 36USB and 38LSB where i mainly talk anybody know which VFO i will need for this?? of is it possible to modify the PLL to go up there?? i pulled a powered D-104 off of another rig and now it out-talks everything else in my shack scott Glad the radio's working out well. Sometime in the past, someone did have a VFO hooked up to that radio. When I got it, there was a cable hooked up to one of the 1/4" phone jacks on the back and connected to one of the crystal sockets. The crystal was taped inside. I had to replace the crystal socket (they had soldered the cable right to the pins), and restored the crystal operation. There is no PLL, it's a crystal rig, so your only practical options are to either get a crystal for channels 36,37,38 and 40, or rewire a VFO. I'm not a big fan of VFO's because they all seem to drift somewhat, which really sucks on SSB. If I were you, I'd just swap out one crystal for the 36-40 replacement. When I aligned the radio, I did so with 23 channels in mind. But I seem to remember the Centurion was faily wide-banded, so you shouldn't see much loss in receiver sensitivity or power output on 36-40. |
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Post by bioman on Jun 27, 2008 12:50:44 GMT -5
now correct me if im wrong <i probably am>
but couldnt i build a box with say 4 or 5 different crystals in it then use a multi-position rotary switch to switch between the "hot" side of the different crystals?
as long as the crystals match up with the oscillator crystals already present......
for example run a 11.3 crystal which when mixed with the osc should give me channels 25 26 27 28 ....a 11.350 crystal set on position 2 of "the box" would give me channels 29 30 31 and 32 and etc
right?
or am i way off base here?
i'd plug it into say the 11.00 crystal slot in the radio and could use channels 1-4 on the radio to select between different frequencies based on the crystal i have selected in the box
does any of this make any sense or do i need more coffee??
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Post by Tombstone (R.I.P.) on Jun 27, 2008 17:12:20 GMT -5
I'm not familiar with the Centurion but if it has a 4-4 synthesizer setup you can use a rotary switch on it with the mixer crystals you need. There's a good bit of wiring to keep the 23 channels.
Tombstone
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Post by Tombstone (R.I.P.) on Jun 27, 2008 17:19:01 GMT -5
Huh, like I say I'm not familiar. If that radio has 23 crystals, one for each channel, then you can pull, say, channel 9 and run a cable to a box with your rotary switch with the crystals you want.
Tombstone
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Post by bioman on Jun 27, 2008 17:36:44 GMT -5
tombstone... thats almost exactly what i was thinking....... here is the crystal chart for the radio www.cbcintl.com/XTALS/SSB%2011000-81665-81635.pdfnow am i right in thinking that each .05 in frequency would give me a new "group" of 4 chennels each? like 11.3 will give me channels 25 26 27 28 ....a 11.350 crystal set on position 2 of "the box" would give me channels 29 30 31 and 32 and etc right? anything special i would need in the circuit? or is it ok if i just ground all the ground legs of the crystals and use the switch on the hot side? i'm eyeballing the 6 position 2 pole rotary switch at rat shack for this www.radioshack.com/product/index.jsp?productId=2062536&cp=&sr=1&origkw=rotary+switch&kw=rotary+switch&parentPage=searchi should be able to run 6 different crystalls with that right? set the box on say position 1 then use the actual channel selector to chose between the 4 frequencies for that particular crystal right? i dont have 23 crystals in the radio..... its a group of 6 "channel" crystals and the 3 different oscillator crystals as shown on the chart.... so if i am thinking correctly i would need to replace one crystal with the box <or even one new crystal>then i would have four new frequencies on those positions of the channel selector right? like if i was to replace JUST the 11.000 crystal in the first position with a 11.300 crystal it would give me channels 25-26-27-28 on the 1-4 positions on the channel selector ...right? hell i dunno i think i am starting to confuse myself LOL |
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on Jun 27, 2008 21:03:50 GMT -5
now correct me if im wrong <i probably am> but couldnt i build a box with say 4 or 5 different crystals in it then use a multi-position rotary switch to switch between the "hot" side of the different crystals? as long as the crystals match up with the oscillator crystals already present...... for example run a 11.3 crystal which when mixed with the osc should give me channels 25 26 27 28 ....a 11.350 crystal set on position 2 of "the box" would give me channels 29 30 31 and 32 and etc right? or am i way off base here? i'd plug it into say the 11.00 crystal slot in the radio and could use channels 1-4 on the radio to select between different frequencies based on the crystal i have selected in the box does any of this make any sense or do i need more coffee?? You're pretty darn close, although your channels are a bit off. Channel 25 is below channel 23 in frequency. It would be one of the channels you skip, every 4th channel due to the RC gap. Channel 24 you can get in the blank spot between 22 and 23 (I don't remember whether I put it in there or not). an 11.300 Mhz crystal will give you channels 26,27,28,and 30. 11.350 will give you 31,32,33, and 35. 11.400 will give you 36,37,38,and 40. And yes you could put the crystals in a little box with a rotary switch and mount it to the radio. But you have to keep lead lengths short to keep the crystals close to frequency. You also have to add trimmer caps to the crystals in order to "net" them in to the exact frequency. Switching the crystals depends on how the radio is set up. Some radios have all the crystals using ground as common (and the trimmers connect to that side) and switch the "hot" side with the selector. Others are the exact opposite. Some radios (and I think the Centurion is one of them) connect the "cold" sides of the crystals together, but run that through a variable cap for the clarifier control to ground, which means you can't directly ground the expansion crystals if you want the clarifier to work (and you do for SSB). Depending on what channels you talk on and how many other radios you have to switch to, it might be less fuss to simply get one 11.400 Mhz crystal for 36-40 and just pull one of the stock crystals out for a bank of channels you don't use, and replace it with 36-40. |
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Post by bioman on Jun 27, 2008 21:15:37 GMT -5
ok i understand how the channel "jump" works now.... couldnt i tie all the ground sides to the ground pin of the crystal socket? i mean if i was to go with a "box" ?? does this circuit look right? www.radiomods.co.nz/xtalswitch.htmlALTHOUGH i MAY just end up going with the single crystal swap scott |
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jun 27, 2008 22:08:06 GMT -5
ok i understand how the channel "jump" works now.... couldnt i tie all the ground sides to the ground pin of the crystal socket? i mean if i was to go with a "box" ?? does this circuit look right? www.radiomods.co.nz/xtalswitch.htmlALTHOUGH i MAY just end up going with the single crystal swap scott If all the ground sides of the crystals are normally tied together you can use the "common side" of the crystal socket. But if there's a trimmer on the "cold" side of each crystal socket before they all tie together, then you'll have to attach your common lead on the other side of the trimmers and provide trimmers inside the "box" to adjust the additional crystals. The circuit you referenced may have trouble working in the Centurion, if the "cold" side is isolated from ground by the clarifier trimmer. |
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Post by bioman on Jun 27, 2008 22:29:16 GMT -5
ok i see what youre saying now......
will have to experiment a bit with a pair of crystals and one switch to see what is what..
so what youre saying <i think> is that i would probably want to tie all the grounds together and run them to the "ground" side of the crystal socket then put trimmers inline on the "hot side of the crystals then into the switch and from there into the hot side of the crystal socket...right?
and use a strictly mechanical switch and not worry about the 12v and the diodes... im not sure what the deal with them is anyhow
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Post by Tombstone (R.I.P.) on Jun 28, 2008 7:55:55 GMT -5
Ok, Sandbagger has you on the right track but as he says, the easiest way is just to pull crystals for the channels that you don't use and swap in the ones for the channels you want. That's the kind of thing that the more you think about it the more confusing it gets.
Tombstone
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Post by 2600 on Jun 29, 2008 0:44:28 GMT -5
If you add crystals and switches, try to keep the wires as short as possible. A convenient spot for a switch may be a long way from the channel-switch wiring. More than a few inches (total) of extra wire in line with a crystal tends to throw it off frequency.
Simple rule is the shorter the better.
73
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Post by bioman on Jun 29, 2008 5:45:45 GMT -5
after much thinking <and confusing myself i believe i am just going to swap crystals so i have 36-37-38-40 in the bank that 1-4 is in right now.......
maybe later one down the road pick up one of the expanders from cbc international......
anybody use one of these kits??
thanx for all the help
scott
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Post by Tombstone (R.I.P.) on Jun 30, 2008 18:54:51 GMT -5
The Expo Expander kits are good but I never tried to install one in a non PLL radio. Don't know if they're still available, I heard that they quit making them??
Tombstone
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Post by bioman on Jul 1, 2008 6:49:12 GMT -5
according to this website www.cbcintl.com/ they look to still be going i dunno what i'm gonna do yet....... little john down the street from me promised to look in his bag o crystals.. OR i need a PAL model A2 he has a PAL chart ...which model goes with which radio....only one i've ever seen...... i'll have to see if he will let me borrow it to scan and put online...... he has a PAL model A7 down there and i THOUGHT i could do the match on the crystals and put it in it but everything i've read says no oh well..... |
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Post by 2600 on Jul 3, 2008 1:08:03 GMT -5
So long as the letter is the same, you should be okay by just subbing the crystal. The pessimistic noises I normally make about 'converting" a PAL concerns folks who want to change the letter-version of their slider. If you look at the PDF file in bioman's link above, the letter indicates the range of frequencies that slider's internal components are set up to cover. In this case, roughly 11 to 12 MHz. The digit following the letter indicates the exact crystal used to match any one radio's internal frequency setup. But the file from PAL's web site doesn't provide the exact crystal frequency for each "digit" type that goes with the "letter" type. There is some room to 'fudge' the dial-calibration coil and trimmer cap if you are using a crystal that is 'close' to the one your radio needs. The PAL's internal VFO runs from 5 MHz to 5.4 MHz, more or less. To sub for the radio's 11.5 crystal would call for a 6.5 MHz crystal in the PAL. Their setup did not contemplate lower frequencies. They assumed you only wanted to go above channel 23. Adding a second crystal on a switch was a popular way of expanding a PAL for lower channels. But the radio AND the slider may prove to be too narrow-banded to cover a range that wide with full power and receiver sensitivity. But the "A" version of the PAL was built to cover from 11 to 12 MHz, with a crystal between 6 and 6.8 MHz. If you change crystals, the PAL will have to be realigned to match it. Just found the PAL web page for their pre-1978 linears and sliders. www.firestik.com/Tech_Docs/Pal_Menu.htmThis is the page where the "Component Reference" pdf file above is found. Also shows an alignment file. 73 |
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Post by bioman on Jul 3, 2008 6:30:22 GMT -5
2600 man i wish ihad known before you didnt have that link i would have sent it over to you if you look all the way at the end of this PDF cbtricks.com/miscellaneous/vco/pal/vco/graphics/pal_vco_1.pdfit gives you a chart that shows EXACTLY which rock should be in which version ...the first group being "A" the 2nd group being "B" etc according to that i need version A-2 which takes a 6.0 rock so iyoure saying i could take an A-7 and put a 6.0 crystal in it and "adjust" it into a A-2? good to know....i know where there IS one with a 6.0 crystal in it that i will know by lunchtime today if i can get...... if that one falls through i KNOW i can get the A-7 down the street so i will have to keep that in mind thanx scott |
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Post by bioman on Jul 6, 2008 8:24:58 GMT -5
ok i'm getting there.......
i got the A-7 from my guy dwn the street and replaced the rock in it with a 6.005 <closest one "inhand" to the 6.00 i should have used....close enough for me at any rate>
retuned the VFO for the right frequency range ...
HOWEVER now it is not "tracking" correctly
by that i mean the frequency on the VFO and the frequency coming out of the radio is not the same.....
now i know there is an adjustment inside to correct that but im not sure that i would want it to be "right" since the VFO only goes up to .370 and i do spend time beyond that
does anybody know of a way to put an external <TX AND RX> counter on this radio ??
i know i could get an "inline" one and it would work but that would only show on transmit so to change frequencies to say 27.385 id have to flip to my dummy load and key the radio as i spun the VFO
this must be a very early model VFO since the manuals on CB tricks are for 3 different versions and they all say "Adjust VFO dial to channel frequency 27.437" and mine doesnt even have .435 on it.....
like i said it only goes to .370 and it says "11 meter slider/scanner" on the front
so anybody have any ideas abou a counter?
thanx
scott
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Post by bioman on Jul 6, 2008 19:11:51 GMT -5
after MUCH playing with this thing again today and with another radio with a headphone jack i finally can make heads or tails of this conversion and have a "road map" for the VFO the VFO DIAL goes from channel 1-2-3 etc to 21 then 22-22A-22B-23-23A-23B 295305 etc to 370 ACTUAL frequencies <after i aligned them to the range that i wanted >go from 26.845 to 27.575 i have a roadmap now so i can get around....but a frequency counter would still be VERY nice for this radio |
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Jul 6, 2008 21:20:01 GMT -5
after MUCH playing with this thing again today and with another radio with a headphone jack i finally can make heads or tails of this conversion and have a "road map" for the VFO the VFO DIAL goes from channel 1-2-3 etc to 21 then 22-22A-22B-23-23A-23B 295305 etc to 370 ACTUAL frequencies <after i aligned them to the range that i wanted >go from 26.845 to 27.575 i have a roadmap now so i can get around....but a frequency counter would still be VERY nice for this radio How's the radio's power output holding over that range? When I aligned it, I was not expecting to have to cover much beyond the stock 23 channel band. So consequently, I did not "wideband" stagger tune the transmit or receive coils, other than the balance channels 1 and 23. I knew a guy who ran a Centurion with a Model 90 VFO back in the 70's, and he could go all the way up to past 27.8 before things started to fall off. So I would imagine that this radio is fairly broadbanded for a 23 channel. Some 23's were lucky to make it to channel 45 before power fell off. |
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Post by bioman on Jul 6, 2008 21:59:41 GMT -5
its doing ok......
little lite on power up above tho...
i MAY end up running it back up to you to retune for me if youd be interested.......
i trust few of these guys down here and most of them don't like wrenching on these older rigs
scott
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Post by bioman on Jul 9, 2008 9:17:27 GMT -5
AHA!!!!! after MUCHO research and some help from nomad <on the CB tricks site> i think i found what i was looking for.... you guys with trams browning etc will want to pay attention here since this is also what you need basically what it boils down to is that i need a PROGRAMMABLE offset display like i would feed it "x" number and it would add "Y" inside of it and display "Z" follow? this kit cgi.ebay.com/FREQUENCY-COUNTER-DIGITAL-DIAL-SEMI-KIT-Low-power-LCD_W0QQitemZ130236388446QQihZ003QQcategoryZ25401QQssPageNameZWDVWQQrdZ1QQcmdZViewItemdoes just that,,,,,,,, now granted there is not different offsets for different modes <unless someone smarter than me can figure that part out> but if you have a center frequency <like set it on AM> it will be close enough to get you in the ballpark then tune someone in on SSB ........... i think... look over the links the dude has on his ebay ad and its a pretty slick little setup and the price is great....... nomad....2600....sandbagger.....spitfire....nightranger....<sorry any tech i may have missed> what do you gus think of this one for what i want to do??? scott |
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Sandbagger
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Post by Sandbagger on Jul 9, 2008 10:33:07 GMT -5
AHA!!!!! after MUCHO research and some help from nomad <on the CB tricks site> i think i found what i was looking for.... you guys with trams browning etc will want to pay attention here since this is also what you need basically what it boils down to is that i need a PROGRAMMABLE offset display like i would feed it "x" number and it would add "Y" inside of it and display "Z" follow? this kit cgi.ebay.com/FREQUENCY-COUNTER-DIGITAL-DIAL-SEMI-KIT-Low-power-LCD_W0QQitemZ130236388446QQihZ003QQcategoryZ25401QQssPageNameZWDVWQQrdZ1QQcmdZViewItemdoes just that,,,,,,,, now granted there is not different offsets for different modes <unless someone smarter than me can figure that part out> but if you have a center frequency <like set it on AM> it will be close enough to get you in the ballpark then tune someone in on SSB ........... i think... look over the links the dude has on his ebay ad and its a pretty slick little setup and the price is great....... nomad....2600....sandbagger.....spitfire....nightranger....<sorry any tech i may have missed> what do you gus think of this one for what i want to do??? scott Sure, those counters have been around for a while now. They are a nice way to give "Cobra 2000"-like operation to just about any radio with a main oscillator that changes with each channel change or a VFO. You have to be careful when you add one of these counters, that you tap it into a place where the counter will not load the oscillator down to the point where you start losing transmit power or receive sensitivity. I just looked at the E-Bay link, thinking it was a finished product. I'm not sure if you want to play with a kludge kit. It's certainly cheap enough, and if you're up for a challenge. Otherwise, look for the external add-on offset counters. |
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Post by bioman on Jul 9, 2008 10:53:48 GMT -5
bah
the "kit aspect" doesnt bother me at all
besides ive been having trouble finding one with PROGRAMMABLE offset <other than a PDC they dont make anymore>
just wish that you could set different offsets for AM LSB USB so that it would read RIGHT on the different modes....
i emailed the builder and he says
QUOTE
"The current version of my frequency counter only supports a single IF frequency as an offset.
You can change this as often as you like, but it's not practical to change every time you change modes.
I have had a number of requests for multiple IF's for a variety of applications, and I am considering adding that. But I have to go to a larger microprocessor." END QUOTE
so i dunno...
im guessing i could set it up on AM and it would put me pretty close into the ballpark....
the LCD module itself is 1.25" X 4.88" so if i do it i'm thinking it might be cool to replace the clock in the centurion with the counter unit
nomad had recmmended coming off of TP4 for a counter then adding the needed offset
scott
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