Amps
[Top] [All Lists]

[AMPS] Blown TL922A... What to do?

To: <amps@contesting.com>
Subject: [AMPS] Blown TL922A... What to do?
From: ki6sz@compuserve.com (Don Kessler)
Date: Wed, 6 Sep 2000 22:32:33 -0400
Tom wrote, 

"Sounds like you have outgassed. You need to take more nichrome...
 
The tank is typically a virtual short for VHF and UHF energy, 
because it has a capacitor shunting the input. All your claims 
about VHF parasitics damaging components are just "arm-waving" 
to sell kits and slam manufacturers...

Mr. Measures fails to understand series resonances have lowest  
impedance, and less impedance than either "component" alone, to 
support his nichrome sales..."

You can say what you will, but in the last couple of years, Rich has been
the only one here who has been able to explain the fundamental problem with
the TL-922 -- lack of parasitic suppression.  I can also tell you from
first-hand experience with well over a dozen formerly unruly TL-922s sent
to me for repair and modification, plus two of my own TL-922s that used to
eat bandswitches, that his suppressers have "tamed the beast."  My judgment
as a BSEE, MSEE, and soon-to-be Ph.D., is that his analysis is sound and
well thought-out.  Additionally, the implementation of his "solution" on
the 14+ TL-922s that I have worked on would further attest to the validity
of his analysis.    

I have never met Mr. Measures, but I have spoken with him several times on
the phone, and he has always been very helpful.  As a happy owner of two
modified TL-922s, I am fortunate to have stumbled upon his website and
found his in-depth analysis of the design flaws in the stock '922 and his
FREE instructions for modifying these amps.  

As for the snide comment regarding his "nichrome sales", his prices are far
too low for him to be netting much money there.  Also, I'm very
hard-pressed to find a local source for this wire that will match his
prices -- especially in such small quantities...  Likewise his parts kits
are very, very inexpensive -- definately a very small profit margin
there...

So, if it is not parasitics that plague the stock TL-922, I would
graciously request that Mr. Rauch and any of the other experts explain why
less than 30 cents worth of nichrome wire (yup - $1 will get you about 5'
of nichrome wire from Rich) stops the TL-922 from self-destructing?  How
about it?  Why not disprove his theory with a better theory of your own? 
I'll be glad to implement "your" retrofit into a TL-922 and see what your
success rate is.  It better be good, so far Rich's analysis is 14-0.  

73 de Don  (ki6sz)

--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com


<Prev in Thread] Current Thread [Next in Thread>