Thanks Jim
Oh boy, yes T2302. I don't know why I said 2802, I guess that's what happens when your old, tired and frustrated. I figured that's where my 13.6 volts was going by following the schematic but wanted to confirm it before I started dissecting T2303 to get to T2302. I wonder if I could put a new lead to T2302 from the bottom side of the card? At least that way maybe I could test it and see if I have to rewind T2302 before removing T2303.
I'll have to study it and see how difficult this is going to be either way.

If someone has a good PA board they want to sell me I'm ready to buy one.

Steve w7jsc

From: "Jim Shorney" <>
Sent: Friday, March 21, 2014 8:14 PM
To: "J. Steven Cochrane" <>; "drakelist" <>
Subject: Re: [Drakelist] TR7 Driver Stage on PA Board Questions

I assume you are referring to T2302, there are no 28xx parts on the PA deck. I suspect what you are seeing is one of the lead wires from T2302, which is part of the RF filtering system for the collector voltage to the drivers. It looks to be bifilar wound, so yes, a break in the common lead would kill 13.6 to both of the drivers. It looks like to get to it you would need to remove T2303. Not an easy task, but do-able. I don't have one in front of me, just looking at SM
pictures right now. Once you can get to it, it shouldn't be a big deal to
either patch the broken lead or re-wind it.



On Fri, 21 Mar 2014 16:21:32 -0600, J. Steven Cochrane wrote:

I have two TR7 questions:

1. There is a VERY fine wire, like fuse wire, that runs next to T2802 toroid (side closest to the final amp stage), it is broken. Could that be why I don't have 13.6 volts going to the Driver Transistors (there is 13.6 volts at the Test Jumper for the Bias Measurement)? The toroid doesn't look all that good either, but neither does the one in my good TR7.

2. Does anyone know of an easy way to replace that wire and T2802 if necessary?

If anyone has a working PA board they would like to sell I'm interested.

J. Steven Cochrane W7JSC

Ham Radio NU0C
Lincoln, Nebraska, U.S.S.A.
TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A,
HyGain 3750, IBM PS/2 - all vintage, all the time!

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