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[AMPS] Bringing old amps back on line

To: <amps@contesting.com>
Subject: [AMPS] Bringing old amps back on line
From: 2@vc.net (measures)
Date: Thu, 16 Nov 2000 09:16:29 -0800
>Hi to all on the list.
>I am sure the topics has been covered in previous threads but I could not 
>find an answer on the archives.
>
>What I would like to know is what steps should be performed when bringing 
>an older amp back to service.
>
>The reason I ask is that I am about to get a second hand Yaesu FL-2100z. 
>The unit is 18 years old with original tubes (I believe they are 572 - 
>haven't seen the unit yet). The gent has owned it since knew, and it has 
>never been used over 200W output as he only has a 200W tuner. It was 
>mainly so he could use it for AMTOR and let the exciter idle for his 200W 
>output. It was last used 2 or so months ago to see if it still worked. 
>Very low hours overall (guess-timation of less than 100)
>
>My questions are:
>    Should I heat up the tubes up for a longer period (not the getter 
>theory again)?
>    Do you run the amp at increasing power levels, what time periods 
>(i.e.. 50W for 5 mins, then increase to 100W etc etc)?
>    My worry is the HV caps for a vintage machine, should they be swapped 
>out, 

yes.  Electrolytics have a finite life.  For longer life, choose 105-deg. 
C rated units.  

>or wait until they die (but that will usually kill something else too)?
>    Any other things to consider?
>
>As I said this will have been dealt with before, but for use "young pups" 
>humour me.
>I will be looking for to some comments from Rich and Tom

Tom and Rich agree that the 572B has too-much grid-L for outstanding VHF 
stability.  Lower Rp parasitic suppressors are helpful.  

cheers, Noel 
>
>PS> The FL-2100z is "rated" at 1500W pep INPUT for SSB what is a rule of 
>thumb for output (I mean real out the coax output), also for 1000W CW 
>INPUT what does that translate into. I know it is a legacy of the days 
>when we had INPUT power limits (I have had my call for 18 years now)
>


-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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