[Amps] Fault protection

[Roger D Johnson]

Tom W8JI wrote:
>> I have an L-4B and L-7. Both have the same HV supply which 
>> uses a 2-watt .82 ohm "fuse" resistor in series in the B+ 
>> line. I have often wondered why Drake did this rather than 
>> use a real fuse though the primary side of the transformer 
>> has breakers. There are 2 50K ohm 50-watt bleeders across 
>> the output but no "glitch" resistor. The bleeders cause 
>> the supply, which is outboard from the RF deck, to run hot 
>> to the touch.
>>     
>
> Maybe it explains it in the manual, but I wonder.....
>
> How do you know it was installed as a fuse resistor, and not 
> as something else like RF decoupling?
>
> It very well might have been a sacrificial part that was 
> poorly thought out, or one that was better than nothing for 
> a fuse. But it very well could have been put there with an 
> entirely different idea in mind.
>
> Whatever the case, we know it wasn't the correct part for HV 
> fault protection. In that case it's more like a reminder 
> something happened. :-)
>
> 73 Tom 
>
>
>
>
>   
According to the manual, it's to protect the rectifier diodes. They say
to replace with IRC
type BTH only.

73, Roger


-- 
Remember the USS Liberty (AGTR-5)
http://ussliberty.org/