[Collins] Re: 75S3 Questions

[Jim Brannigan]

Gloss white would be better.  The ceiling white was open.....

Jim



>I spray a bit of glossy white spray paint in the lid of the can and use a
> small brush OR I mask the glass and end of the meter barrel and paint the
> inside of the case with the spray.  Ceiling paint isn't reflective enough
> for me.  I do that with all the S Line meters.
>
> Ian, K6SDE
>
> -----Original Message-----
> From: collins-bounces at mailman.qth.net
> [mailto:collins-bounces at mailman.qth.net] On Behalf Of Jim Brannigan
> Sent: Tuesday, February 12, 2008 2:20 PM
> To: geraldj at storm.weather.net; collins at mailman.qth.net
> Subject: Re: [Collins] Re: 75S3 Questions
>
> Antique Electronic supply had new replacement capacitors for the B+.  The
> cans are too small to restuff.
>
> I tore down my 75s3B, removed the PTO, meter, tubes, mechanicals, etc and
> gave it a good cleaning and greasing.
> As part of the project, I opened the meter and painted the inside case 
> with
> some left over white ceiling paint.
> It helped some...
>
> Jim
>
>
>
>> On Tue, 2008-02-12 at 15:28 -0500, Bill Stewart wrote:
>>> Man, what a great response to my questions. Many thanks to all who
>>> responded.
>>>
>>> I have shut the receiver down, except for some testing. In previously
>>> looking around the rcvr, I did note that there were only five of the
>>> paper,
>>> tubular capacitors...all Sangamo and I believe either .1 or .05's. They
>>> will
>>> be replaced. The coupling cap to the grid of the 6BF5 is a disc. I think
>>> disc caps usually hold up ok, but will check the 6BF5 grid bias.  Also,
>>> someone mentioned the bias rectifier being a S/T cube...that's what I
>>> have.
>>> I will replace it with a 1N4007, same as used for the B+ diodes.
>>
>> Mount a two terminal without ground terminal (solder tag) strip in place
>> of the selenium and mount the new diode on that. There's a strong chance
>> that will cool both the 6BF6 and the power transformer, though the tube
>> will alway be fairly hot. Hence the dark spot on the cabinet lid over
>> it.
>>
>>> It does
>>> have 150vdc B+. I think the fuse-block diode mounting was orig with this
>>> rcvr since the mounting nuts have some loc-tite on them.
>>
>> Shouldn't have been loc-tite, but a colored lacquer also on the solder
>> connections. The inspector put a drop on each inspected and passed
>> solder connection.
>>>
>>> The B+ 'lytic in my rcvr is a Sprague with twist lock tabs, 183-1764-00
>>> (may
>>> be a Collins in-house number).
>>
>> That IS the Collins part number. The 183 group was all electrolytic
>> capacitors.
>>
>>> It is 40/40/40 uf @250vdc. It is about 1 inch
>>> in dia. The ones I found at Surplus Sales was 40/40/20 at 450vdc 1.5 in.
>>> dia
>>> and another was 40 at 350vdc and 40/40 at 300vdc 1 3/8 in. dia. I'm not
>>> sure
>>> if either of these would fit the chassis slots for the twist tabs. 
>>> Anyone
>>> know for sure. I may try my hand at restuffing first.
>>
>> They did come in different mounting diameters and the big ones won't
>> stuff into a small hole even with a big hammer.
>>
>>>
>>> I did receive the manual on cd today and its the forth edition, 1 jul
>>> 1963.
>>> It's not the exact manual for my rcvr but will do for a while.
>>
>> Probably for 3B/C. Won't match your receiver several places. Was hard to
>> read. I wrote the next edition.
>>
>> The right manual should be down loadable from CCA manuals.
>>
>>> By the way,
>>> if anyone needs to copy this version of the manual, let me know and you
>>> can
>>> borrow my cd.
>>>
>>> On the S-meter illumination, I noticed the inside of my S-meter is 
>>> black.
>>> The inside of my 30L1 meter is white.
>>>
>>> Guess that brings me up to date for now. I have some other questions re:
>>> hum
>>> and some squealing at close to max volume. These problems may go away
>>> after
>>> I re-cap so will hold off on these questions.
>>
>> Signs the big electrolytics are bad (as are the couple little ones).
>>>
>>> Again, many thanks for all the help...it IS a real nice rcvr...73 de 
>>> Bill
>>> K4JYS
>>>
>>>
>>
>> -- 
>> 73, Jerry, K0CQ, Technical Advisor to the CRA
>> All content copyright Dr. Gerald N. Johnson, electrical engineer
>>
>