[ARC5] Receiver audio transformers and other stuff.

[Brian Clarke]

If the neon tube across the primary becomes disconnected, and if the output 
on the transformer is disconnected, and if there is a very loud noise, eg, 
lightning crash, then the primary will likely fail open circuit.

73 de Brian, VK2GCE.

----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: "ARC-5 List" <arc5 at mailman.qth.net>
Sent: Monday, January 21, 2013 10:11 AM
Subject: Re: [ARC5] Receiver audio transformers and other stuff.


> On 20 Jan 2013 at 16:05, Bill Cromwell wrote:
>
>> > hacking.  None were ever made without one or the other of the four
>> > transformer variants.
>
> Yes. ALL came with output transformers....always.
>
>> Thanks for your reply. I suspected none of them were built that way. I
>> don't know if somebody yanked out a good transformer for some funny
>> mod
>
> ALL BC band ARC-5s which were hacked into "Hi-Fi AM Tuners" had the
> output transformers and the BFO transformers removed...among other
> despicible things done to them.
>
>> or used that circuit because the original transformer opened.
>
> Hardly ever...
>
>> Ken
>> was asking about open transformers. Was there actually a mod that
>> called for getting rid of the output end of the radios?
>
> Several, in fact. They turned the output stage into a resistance-coupled
> driver to a following audio amp.
>
>> Maybe somebody
>> didn't know how to use a matching transformer.
>
> More than likely...
>
> What I was asking was if the collective wisdom had seen enough defective
> audio transformers to tell if there was a common failure mode.
>
> So far, it appears that unless those transformers had been abused
> somehow, they never failed.
>
> I was quite surprised to find this one with a completely open primary:
> however it IS one of the first (oldest) ones out there.
>
> I suspect, from the appearance of the rest of the really glorious hacking 
> job
> done on this particular receiver, that the audio stage had been severely
> abused some way.
>
> Ken W7EKB
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