[ARC5] On Hacking - 100 watt ARC-5s

[Mike Hanz]

On 10/16/2012 2:25 PM, Kenneth G. Gordon wrote:
> On 16 Oct 2012 at 14:15, Mike Hanz wrote:
>>   I'm not sure how he was cooling
>> them...
> Leave the cover off.

That's certainly a classic solution, Ken.  But then you are radiating 
the harmonics directly from the original instigators of the distortion.  
He had very carefully screened every opening in these particular ARC-5 
transmitters, making a thoughtful effort to keep everything inside a 
Faraday shield until the signal had traversed a filter.  Since these are 
single frequency range transmitters (40 and 80), he had a bit easier job 
accomplishing that.  I think he mentioned he "might have" used the Naval 
Research Lab's considerable test capability to fine tune the TVI 
performance.  Like I said, he was a very knowledgeable engineer, living 
in densely populated Washington DC.  Being a government employee, he had 
to consider that annoying the neighbors might have undesirable 
consequences.  At least that's what he told me when he gave them to me.  
I didn't think at the time to ask him if he used forced air cooling.  
Perhaps he didn't bother, just accepting the chore of changing out tubes 
occasionally.  I'll have to dig them out one of these days and put some 
photos of them on my website.  I think they satisfy the criteria of an 
interesting modification by an amateur to accomplish a specific purpose, 
if there is such a category.

73,
Mike  KC4TOS