Amps
[Top] [All Lists]

[AMPS] Transformers

To: <amps@contesting.com>
Subject: [AMPS] Transformers
From: km1h@juno.com (km1h@juno.com)
Date: Tue, 9 Mar 1999 10:57:34 -0500


On Tue, 9 Mar 1999 09:02:24 -0000  Peter Chadwick
<Peter_Chadwick@mitel.com> writes:
>
>Rich says:
>
>>?  Many models of Henry amplifiers do not use a peak 
>discharge-current 
>>limiting glitch resistor is series with the hv positive lead.  Most 
>of 
>>the hv transformer failures I have heard of in Henry amplifiers were 
>
>>associated with a noisy arc in the RF output compartment.  .  
>
>Rich, what was the failure mode? Open circuit, shorted turns, or 
>insulation
>breakdown?
>
>My only experience with HV xfmr failure has been insulation breakdown. 
>That
>was using an (unpotted!) 1200 - 0 - 1200 in a FW bridge, in a remote
>controlled  amp out in the garage. 
>
>Should have known better - 1) xfmr not intended for that many volts 
>from
>winding to frame. 2) using an unpotted xfmr in a damp location.
>
>It was a risk that didn't work out. However, it leads me to concur 
>with Rich
>about the desirability of potting - unless you can get a mil grade
>hermetically sealed oil filled job (that isn't leaking!)
>
>73

Peter, do you mean completely potting in tar as was done ages ago?
I have not had or noticed problems with open frame xfmrs that are vacuum
sealed/impregnated.
The failures I see are the SB-220 and NCL-2000 potted types that fail
from heat when pushed by contesters.
Have not heard of any open frame failures as used by DX-peditions
either.The still popular MLA-2500 is one example.

On another thread, is there any particular advantage to the buck-boost
primary tap selection as now championed by Ameritron?

73  Carl  KM1H
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com/getjuno.html
or call Juno at (800) 654-JUNO [654-5866]

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


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