Thanks again Joe,
Very informative , though I swear my archive searches fail to turn up such
nuggets, must be my search terms hi hi! The original part is a 26-131, says
so on it, and I'm confident that the replacement is a 26-164. Given the
improved voltage rating and relatively easy replacement it seems I'm in luck
so far. Have located SB-221-2 bulletin which details the change and parts so
looks like I will be good to go with the new part when the time comes.
Martin, HS0ZED
-----Original Message-----
From: Joe Subich, W4TV [mailto:lists@subich.com]
Sent: 19 October 2010 12:22
To: Martin Sole
Cc: amps@contesting.com
Subject: Re: [Amps] SB220 tune capacitor
Martin,
> I might be looking for the special end plate then, or at least some >
pictures to see if I can fabricate one.
I had to do some review but now that I looked at some SB-220 pictures, it
seems that what they did was use a threaded stand off between the tuning
capacitor end of the 10 meter coil and the lug on the end of the coil. The
coil remained in position but a 1.5" or so aluminum stand off filled the
space to the plate.
Here is a link to the archives of "Amps" that describes the change:
http://lists.contesting.com/archives//html/Amps/2006-06/msg00118.html
From memory the stand-off "DA" was either 6-32 or 8-32 (which ever matched
the screw holding the 10 meter coil to the bracket with the blocking
capacitor) x 1.5."
73,
... Joe, W4TV
On 10/18/2010 10:43 PM, Martin Sole wrote:
> Thanks Joe,
>
> I might be looking for the special end plate then, or at least some
> pictures to see if I can fabricate one.
>
> 73
> Martin, HS00ZED
>
>
> -----Original Message-----
> From: Joe Subich, W4TV [mailto:lists@subich.com]
> Sent: 19 October 2010 09:22
> To: amps@contesting.com; hs0zed@csloxinfo.com>> Martin Sole
> Subject: Re: [Amps] SB220 tune capacitor
>
>
> > Did the tune capacitor change during the life of the SB220 or>
> perhaps with similar amplifiers? SB200 HL220 etc.
>
> Yes, later SB220 had a higher voltage breakdown (wider space, more
> plates) capacitor that was longer. It generally came with a special
> end bracket for mounting the 10 meter coil.
>
> 73,
>
> ... Joe, W4TV
>
> On 10/18/2010 10:07 PM, Martin Sole wrote:
>> Perhaps a question for the Heathkit history buffs.
>>
>>
>>
>> Did the tune capacitor change during the life of the SB220 or perhaps
>> with similar amplifiers? SB200 HL220 etc.
>>
>>
>>
>> I have received a replacement capacitor, well it's in UK awaiting
>> onward shipment. From a picture of the actual part sent to me it
>> appears to have two differences with the original part, these being
>> that the ceramic insulators are mounted outboard of the aluminium end
>> plates whereas on the original they are inboard and secondly that the
>> number of fixed / moving vanes is 21/22 as opposed to 18/19 on the
>> original part. I am awaiting confirmation of mounting hole spacing
>> which might be the most significant issue, assuming the min C is not
>> now
> too high.
>>
>>
>>
>> Any thoughts?
>>
>>
>>
>>
>>
>> Thanks
>>
>> Martin, HS0ZED
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|