[Drake] TR7 PA problem: solved!

[ik2bcp - Guido Tedeschi]

It seems that the problem was mainly on predriver trimmer not correctly 
adjusted and, maybe, on too much long pins of transistors and some poor 
joint.
I resoldered all transistors and all the components with solder joints 
looking not good and now the power is fine.
I discovered that this radio needs also a complete alignment: the missing 
sidetone was only a "zero beat" adjustment of C1136 and some othe 
adjustments are not correct.
Still some work to do, but now I can see the end ;-)
Thanks and 73
Ciao
Guido


----- Original Message ----- 
From: "Garey Barrell" <k4oah at mindspring.com>
To: "ik2bcp - Guido Tedeschi" <guido.ted at tin.it>
Cc: <drake at mailman.qth.net>
Sent: Monday, February 14, 2005 12:22 AM
Subject: Re: [Drake] TR7 PA problem: solved!


> Guido -
>
> So there were no defective components, just poor solder joints. ??
>
> Make sure the CW sidetone level control is not turned all the way down. 
> Accessible  _through_  the Key jack on the rear panel.
>
> 73, Garey - K4OAH
> Atlanta
>
> Drake C-Line Service Manual
> <http://hr99.home.mindspring.com/R-4C_Servicez/>
>
>
>
> ik2bcp - Guido Tedeschi wrote:
>
>> The TR7, I have here to repair, is now putting all the correct  power 
>> into antenna!
>> After I resoldered all the transistors and suspect components on PA board 
>> and correctly adjusted the pre-driver trimmer, now the radio is pushing 
>> 110W on 10m and even more power on lower bands.
>> I want to thanks all the people of this marvelous mailing list for the
>> valuable help received.
>> 73 and thanks
>> Ciao
>> Guido, ik2bcp
>>
>> P.S. It remains another problem, missing sidetone on CW, but I write 
>> another
>> message ;-)
>>