Re: {Collins} 30L-1 strange looking power supply board



I had a 30L-1 with one of those installed and although it was working fine, I replaced it for the following reasons:
It was old and capacitors have finite life
I didn't like how the resistors were at the bottom of the assembly, looked like they ran too hot, and heated the aging capacitors I didn't like how the assembly restricted air flow out of the hv compartment. I prefer the Young Kim design philosophy which I installed as a replacement. I don't remember any difficulty with the changeover or modification to wiring or meter circuit. The biggest difficulty was removing the board which explains the rounded corner---only way it will go in there.
Changing to Young's board reduced the heat overall
Paul K0UYA
-----Original Message----- From: Rick Poole WA1RKT
Sent: Wednesday, November 05, 2014 6:35 AM
To: collins
Subject: Re: {Collins} 30L-1 strange looking power supply board


From: "David Harmon" <k6xyz@xxxxxxxxxxxxx>
Sent: Wednesday, November 5, 2014 12:50:20 AM

can you post a picture of the board...possibly on a website

Good morning, David.

I could, but it'll be difficult to see very much without removing the board, which from the way it was wired in, looks like it will be more difficult than it normally should be.

Someone else sent me a photo of the bottom of an early Yves Patuard board which looks pretty much identical to what I have as best I can tell (again, without removing the board).

I have received several private replies to this (it surely seems like other 30L-1 restorers would benefit from these types of conversations if people would reply to the reflector instead of privately all the time, but maybe not...). One person mentioned Steve Pituard or Patuard and a few others have mentioned Yves or Yves Patuard. I'm assuming those are the same person?... or maybe brothers or father/son or ?? Anyway it does seem like that is the board I have, particularly with the distinctive trapezoidal shape with one of the corners rounded off.

Anybody know when Steve/Yves started selling these boards, and when he stopped? (I know he's a silent key now...)

One person mentioned that the Yves board "did a destructive change to the wiring to the meter". Not sure what "destructive" means in that context... presumably any wiring change can be reversed at greater or lesser amounts of effort... perhaps the context was restoring the amp to its exact original configuration which, trust me, is not worth the effort on this one... it'll never be considered collector- or museum-quality, nor do I especially need it to be.

This board seems to work well enough, and I'm from the if-it-ain't-broke-don't-fix-it school, except that the PCB area underneath the bleeder resistors (100K 2W) seems rather badly burned in some places. I don't have a schematic but from the photo of the bottom of the board that someone sent me, it looks like the bleeder resistors are connected in series-parallel so that there is effectively 50K ohms at 4 watts across each capacitor. Unless my arithmetic is off, each resistor pair will dissipate 2.22 watts... well within the resistors' ratings but I'm sure they will run mighty warm. No doubt they would have benefitted by being spaced up off of the board a bit, to allow air all the way around, rather than being mounted flat against the board the way they were. Anybody remember if the Yves board came as a kit, or assembled? Overall, the workmanship shown in the modification doesn't look like the best.

Anybody know what the maximum value of the bleeder resistors should be? I'm thinking of maybe replacing those bleeder resistors with something of a higher value that will run cooler, and spacing them properly up off the board.

Rick WA1RKT
Londonderry, NH
Catch me on 14.300 MHz Intercon / MMSN most days
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