{Collins} Re: 51j-4 mech filter B+ mod



At this point I just left the original plate load resistor in place that
originally fed the bottom of the mech filters, but I will swap a choke in
there. Would I also need a bypass cap between the choke and ground on the
B+ side of the choke, similar to the 75A-4 second mixer plate circuit
that immediately preceeds the mechanical filters? thanks again, dave

> Hi Dave:
>
> You need a load for the tube on the input side.  It is high impedance,
> and need not be tuned.  I recall that a 2.5 mh rf choke will self
> resonate somewhere close enough.
>
> The actual impedance is still determined by the mech filter, even
> though is it only capacitively coupled.
>
> 73,  Colin  K7fm
>
> -----Original Message-----
>>From: daveaust@xxxxxxx
>>Sent: Dec 21, 2006 8:59 AM
>>To: collins@xxxxxxxxxxxxx
>>Subject: {Collins} 51j-4 mech filter B+ mod
>>
>>when taking b+ off the mech filters do I need 500kc L-C tank for plate
>> load or is b+ straight to the plate  with my coupling cap to the
>> filters ok? I don't have a schematic of a workin mod to go by. thanks,
>> dave, n5wnm
>>
>>
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>> AM Net: 29.050 Mc-1200 Central



Sponsored by the Collins Collectors Association http://www.collinsradio.org
Nets: Tues: 3.805 Mc-2000 Central / Thur: 3.875 Mc-2000 Central
Fri: 3.895 Mc-2000 Pacific / Sun: 14.263 Mc-2000 UTC
1st Wed (of the month) AM Net 3.880 Mc-2000 local (ET, CT, MT, PT)
Sun AM Net: 29.050 Mc-1200 Central






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