[Top] [All Lists]

Re: [Amps] Henry 3K-A choke failure...workaround?

To: "'amps'" <>
Subject: Re: [Amps] Henry 3K-A choke failure...workaround?
From: "David Harmon" <>
Date: Thu, 26 Sep 2019 22:17:20 -0500
List-post: <>
I bought a new 3K-A in 77' from the Henry Los Angeles store and picked it up
at the factory.
Two years later the choke went to ground just like Jeff's unit....but his
lasted a lot longer than mine did!
I ordered a new Dahl choke and put it in the center tap and had no more

You cannot put the original choke with the winding that is already grounded
in the CT of the transformer. others have said...insulate the choke from ground and it might
last awhile longer.
The Dahl choke I bought is not insulated from ground....because the winding
does not already have a ground on it....kaff...kaff

I mention all this because it is a fairly well known fact that all the Henry
amp transformers and chokes from that era were prone to failure.
I remember asking a guy at the factory why there were so many failures and
he said the quality was poor because they were cheaply made by some guy in
his garage!
So 3K-A has given very good service and the original xfmr is
hanging in there.
While I had it all torn down to replace the choke I bought a vacuum relay
from RF Parts and replaced that horrible ear shattering antenna changeover
relay with the dime sized contacts.
That was 1979 and haven't had it open since.


David Harmon
Sperry, OK

-----Original Message-----
From: Amps [] On Behalf Of Ron
Sent: Thursday, September 26, 2019 10:00 PM
To: amps <>
Subject: Re: [Amps] Henry 3K-A choke failure...workaround?

   Jeff wa1hco millar wrote:

> Hello wise ones...

> Bought a nice 3K-A at a flea market and made one SSB contact.  On the 
> second contact it tripped off on HV overcurrent.  After some 
> debugging, the Plate choke is leaky to ground at HV but open with an Ohm
> Can I just put the choke up on insulated standoffs?

> Any other suggestions?

   It is a pleasure to be helpful.

   The CURE is to put it in the ground side of the circuit, typically where
the rectifier or the grounded side of the transformer goes to ground.

   Ron  KA4INM - Understanding is much better than
                                       knowing how.
Amps mailing list

Amps mailing list

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