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MK4
Aug 11, 2008 20:10:31 GMT -5
Post by gtr86 on Aug 11, 2008 20:10:31 GMT -5
Just picked up a MK4, no TX and no ch readout?
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MK4
Aug 11, 2008 20:33:25 GMT -5
Post by mark4 on Aug 11, 2008 20:33:25 GMT -5
No channel readout means the PLL is out of lock. Could be a blown ROM chip or another failure in the PLL etc. The radio will not key up when the PLL is out of lock. The radio is 30+ years old and will need a major overhaul to say the least.
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MK4
Aug 12, 2008 1:01:47 GMT -5
Post by 2600 on Aug 12, 2008 1:01:47 GMT -5
Believe him.
He knows.
And if you fancy this type radio, look for a Mark 4-A.
The "A" version was an upgrade that fixed a lot of built-in breakdowns that would shut down the transmit in the original "4" version.
A lot of them.
A Mark IV-A will still be 30-plus years old, but the 100,000-mile tuneup is nearly always a LOT cheaper, maybe by half, compared to the average 400 to 500-buck and up price to PROPERLY rehab a Mark IV.
73
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MK4
Aug 12, 2008 8:11:25 GMT -5
Post by gtr86 on Aug 12, 2008 8:11:25 GMT -5
What is the difference in A version? New to the MK's, thanks
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MK4
Aug 12, 2008 19:11:36 GMT -5
Post by sandman3 on Aug 12, 2008 19:11:36 GMT -5
check the -9 volt supply that comes from the receiver if that supply voltage is off the pll will go out of lock also.. this is on a mk 4 only,not the mk4a
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MK4
Aug 12, 2008 20:03:57 GMT -5
Post by gtr86 on Aug 12, 2008 20:03:57 GMT -5
OK, I need to find a schematic to find the pinouts on the plug then to test for the -9, also what is the difference between the Std and the A model, I am new to MK's so bear with me a little, I know Trams better but have no clue about these brownings, so help if you can, thanks
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MK4
Aug 13, 2008 23:09:25 GMT -5
Post by gtr86 on Aug 13, 2008 23:09:25 GMT -5
I called a place in Rockford IL today and was told they are not taking any work, kinda rude to me on phone, guess they are full and refused work, must be a good shop if you cannot even get a radio in to be looked at,
So again how do you tell the differences in a STD and A Model? Is there a big A on it?
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MK4
Aug 13, 2008 23:22:30 GMT -5
Post by Afterburner(OT-749) on Aug 13, 2008 23:22:30 GMT -5
As simple as this reply might sound, and it is not meant to be being smart, on the face of the radio it will say Mark IV A.
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MK4
Aug 14, 2008 0:11:05 GMT -5
Post by 2600 on Aug 14, 2008 0:11:05 GMT -5
Ummm. Okay. Here's an old post on the subject: grumpy.proboards11.com/index.cgi?board=OWNERS&action=display&thread=1595&page=1#8480And in the interest of "fairness and balance", here's another forum member's perspective on the troublesome Mark IV transmitter design: grumpy.proboards11.com/index.cgi?board=OWNERS&action=display&thread=1831The transmitter is the BIG difference. A dozen-plus chips behind the channel digits in the IV was shrunk down to three (I think) in the IVA. Big improvement in reliablity and power consumption. The transmitter's PLL section in the long aluminum box found in the IV contains nine old-tech power-hungry chips. Besides, it can be cantankerous about locking onto a channel frquency. The IV A shrinks this down to two chips. Again, a big improvement in reliability and power consumption (spelled "heat"). If the newer chips found in the "A" radio had been available in 1973 or 74 when the original IV was being designed, Browning probably would have used them in the first place. But chip technology was developing pretty fast at the time. By the time Browning had gotten their new "digital" design to actually work, it was obsolete. Sound familiar? 73
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MK4
Aug 14, 2008 9:28:16 GMT -5
Post by gtr86 on Aug 14, 2008 9:28:16 GMT -5
2600, thanks for all the info, this is what In wanted, sorry for the redundant questions that prob have been answered to every newbie on here, may be time for a sticky?
afterburner thanks also, I have never seen then a "A" model in person yet, just the STD's.
Well this radio is showroom condition, almost new box smell looking so I am really now trying to figure out if I want to save it or try for a A model and throw this on a shelf until I can get someone that know these radio well to look at it .......huuummm
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MK4
Aug 14, 2008 11:02:23 GMT -5
Post by Afterburner(OT-749) on Aug 14, 2008 11:02:23 GMT -5
Trust me ... you will know when you have a MK IV A compared to a MK IV.
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MK4
Aug 14, 2008 21:11:22 GMT -5
Post by mark4 on Aug 14, 2008 21:11:22 GMT -5
gtr86 check your messages.
I found a NOS browning MarkIV receiver in the box a couple of years ago. Within a couple weeks I located a transmitter that someone screwed up the power cord on. It took out all the filaments on the tubes and the ROM. Repaired it and it worked great. They also convert very nicely with a custom programmed ROM. But I wanted a IVA (this was before I built my own new IVA). So I converted it to a IVA and put the so called brass plates on it. I still have a NOS set of them. Getting back to the point of the only real difference between a IV and IVA is the readout board and PLL. Performance of the transmitter is the same. The design did not change. Same audio and transmit. Same boards! If you love brownings get it restored. Sounds like you have a keeper.
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MK4
Aug 15, 2008 7:44:39 GMT -5
Post by Dr. Rigamortis on Aug 15, 2008 7:44:39 GMT -5
I would restore it too. I have a Mark IV, had a IVA, but I love it the same. Operates great, I have no problems with it, and I have been running it almost every day for 3 years. I have owned it for 10 or more, but just started using it when I bought my own house. I've been running my Mark III recentley because its a new toy, and fun to mess with, but when I want to talk serious!, I get the IV out...LOL
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MK4
Aug 15, 2008 19:27:48 GMT -5
Post by mark4 on Aug 15, 2008 19:27:48 GMT -5
I departed with my totally restored overboard MarkIV. I rebuilt my Pll and readout boards. But the problem I had when I first got it was someone installed various versions of chips in this thing. Don't use LS or CMOS type chip in this radio they will glitch! I worked on that baby and made it like new over a few years. The guy that bought it from me drove 5 hours. And is happy as can be. But I still have 3 more. ;D
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