Tram D201A with PLL Mod

[oldtramlover]

I have and still enjoy this Tram I picked up about 5 to 6 years ago. Mod is no crystals. Replaced with a PLL board out of a Radio Shack radio. Even has digital channel display. Top quality mod. Such quality that there are no additional holes drilled or weird wires. In about 30 mins can convert back to crystals and you would never know it was a PLL Tram.

Spoke with the maker about the same time ago. He was into converting DAK's with Cobra 2000 boards and Trams with the PLL boards. Apparently he did many of them over a 10+ year period. So there must be someone else out there with one of his modded radios. Looking for information on this mod. Radio will be for sale soon and would like to gather information for the next owner.

Anyone else seen this??

[Bigears]

Can't help with any info, but how about some photo's of the PLL board in your Tram, someone may be able to pick the model it came from etc?

I would love to know more about this mod.

[mark]

Interesting...!! I have only seen one and it was in Ohio back in about 1997 I think. It was a Tram D201A with a digital channel display as you have described. I never knew who did it. It seems as though you might be correct in that the guy did a few of them. Very cool idea and I'd entertain doing that to mine if somebody could clue me in to which radio gives us the correct output for the Tram. if you still have contact with the guy, please ask him if I could talk to him. Thanks for posting.

[crazybob]

Here's a pic of a PLL Tram from my picture collection. ..(cheaper than collecting radios.)

[Sandbagger]

Dec 1, 2009 19:29:34 GMT -5 crazybob said:

Here's a pic of a PLL Tram from my picture collection. ..(cheaper than collecting radios.)

It's probably no accident that most of these PLL mods have been done to D201A's. Considering the problems with the self-destructing channel selector switch, which essentially turns the radio into an expensive door stop, reworking it with a PLL synth is not much more trouble than trying to retrofit a newer channel switch.

[cbrown]

Dec 1, 2009 19:29:34 GMT -5 crazybob said:

Here's a pic of a PLL Tram from my picture collection. ..(cheaper than collecting radios.)

Tougher to transmit on, though. Very impressive installation.

[rjordan]

Does the manual VFO still function on this conversion? I couldn't tell from your description if the entire synthesizer board had been taken out, or if the PLL board was added while still keeping the original synthesizer board in place.

I'd love to see a picture of the inside if you ever have the time.

Thanks,

Rick

[oldtramlover]

After posting this and seeing no traffic I stop checking it. Came by the post today and WOW Was glad to see someone else has one.

Yes my VFO still works no issues on my PLL Tram. I'll post some more detail inside pics later today..

[2600]

Does it look like this on the inside?

To start, I did NOT do this mod. I have no ide who did. This radio came in for routine maintenance and I snapped these pics while it was here.



The two red digits were hand-wired onto a RatShack perfboard. And a fine job they did.



Here's what is mounted in place of the original board full of crystals. Looks like it took two of the original crystal baords to set this up. And both boards have been extensively modified.



Here is a wider view showing the metal shield can that contains the PLL circuit. It was made by Uniden, and used in 1978-model AM CB radios, mostly mobile models.



And this what's inside the metal can. A uPD858 PLL chip and all the associated circuits to make a PLL frequency synthesizer. This could have come from a Cobra 77X or any of a handful of other 1978 CB models. The channel-selector switch is hidden from view, but also came out of the same radio. There is a list of models like this at tubesplus.tripod.com/tubespluscom/id9.html



This appeared to be a well thought-out and solid setup. Looks downright labor intensive, to boot.

73

[oldtramlover]

Yes that is the radio exactly.. Thanks for saving me the time to take the pics. I also placed a PDC Freq counter on the top and the pll selector switch is on the back between the slots so no holes drilled in it. Works great no issues, just don't use the radio as much as I should.

The guy who did these mods also was putting Cobra 2000 boards into DAK X's Bet that was a good one as well..

Hopefully someone will make me an offer on it.

[2600]

Makes it sound like this is the same mod, but not the same radio. Forgot to record the serial number with the picture files. But they are dated November of 2007. If you have had the radio 5 or more years, it's not the exact same unit in my pics. Only the same mod.

It's a well thought-out and professionally installed upgrade, and NOT a high-school science-project "hack" job. Should totally fix the "channel switch" problem that doomed 90 percent of the 40-channel D201A radios. And it should outlast the rest of the stuff in the radio, more than likely.


73

[FIXR]

(The channel-selector switch is hidden from view, but also came out of the same radio.]

Actually the channel selector probably came out of either a Cobra 21XLR or 29XLR. It has to be the three section type with the front sections activating the channel display and the rear section for the PLL. The Cobra 77X or RS TRS452 channel selector was a single section activating the PLL and the channel numbers were on the knob.

Fixr

[2600]

I stand corrected. That radio did indeed have a "23-channel style" channel knob with the 40 channel numbers printed onto its outer ring. That selector won't work with LED displays.

And I think some of the radios that used this PLL module were 1977 models, and not 1978.

It's easy to forget details from 30-plus years ago.

73

[Sandbagger]

Dec 16, 2009 1:33:02 GMT -5 2600 said:

I stand corrected. That radio did indeed have a "23-channel style" channel knob with the 40 channel numbers printed onto its outer ring. That selector won't work with LED displays.

And I think some of the radios that used this PLL module were 1977 models, and not 1978.

It's easy to forget details from 30-plus years ago.

73

Some of the radios were even older. The first PLL 23 channel units, like the TRC-152, used that PLL "can" but with a 23 channel switch. The only difference between that and the 40 channel radio was the switch and the VCO block (UHIC-001 vs. 003).

But it is starting to get a little hazy remembering 35 year old trivia.......

[mark]

VERY COOL!!!! That is some real old school quality work there!! I like my std. analog dial fine but that conversion is 100% NICE!!! It was clear that the person doing it was not just a "radio technician". They considered themselves an artist of some sort, otherwise the care and attention to detail would not be there... If the guy is still alive, I tip my hat!!!