{Collins} Re: Help! Newbie restoring a pair of gold dust twins



Hi Paul,

First, congratulations on your "deal".  Good value.

Second, I would recommend that you get a copy of my CCA quarterly on 'The
Care and Feeding of the KWS-1". If you can not get a copy locally, I can
make you one and send it off to you. This quarterly has a lot of info on
restoring and bring up a KWS-1.

I have some immediate comments. Blower hose is just like radiator hose and
make a trip to the local Auto Parts store and find some straight stock that
will fit. Lots of time you can find a piece that has a 90 deg on one end and
make it easier.

Second - Run down all mods and take it back to stock before you even turn it
on. IMMEDIATELY get rid of the solid state rectifiers. Some Collins rigs
will handle solid stating pretty well. The KWS-1 will not. Just because
someone gets away with it does not mean it is all right. I will not go into
the details here (See quarterly covered it there well) but in the early 50s,
the HV components they used were marginal at best even when new and with age
and microcracking of the compounds used, you do not need more stress on the
HV components. The HV choke is a particular concern.


There are a number of selenium rectifiers (little black cubes of molding
compound - with two terminals - on a stud). Be very suspect of these. They
can be replaced with a 1N4007 quite easily and I like to zap the heck out of
the selenium and then mount both the replacement small 1N4007 and the
necessary wires on the resulting open circuit diode to keep it looking
original - but that is just my craziness. You can usually hide the diode on
the side that does not show as much. There are seleniums in both the exciter
head and the P.S. Also be careful of the service bulletins and do the one
that adds the clamp diodes across the keying relay or it will keep getting
carbonized contacts. Also be sure to do the PA tune and load
resynchronization process or it will not tune right. It is in the manual and
covered in my quarterly. It is highly likely that it has been manhandled a
bit in moving and storage and can get bounced out of sync pretty easily.

Check for proper voltage levels around the "Black Beauty" molded caps right
away or check them for leakage and replace any that are suspect. They are
particularly prone to failure - they had a built in failure mode - and be
particular sensitive to the ones in the ALC circuit and the VR circuit in
the Power Supply.

The holes along the front of the sides are for the rack mount kit and are
stock. Do not worry about them.

If you have question, give me a call.

Oh, the matching Saint James Gray paint can be obtained through Nebraska
Surplus. It works well for touch up.

Have fun.  Again, good deal.

Regards,  Bill

N7OTQ
K0CXX Mogollon Rim Collins Collectors Club


----- Original Message -----
From: "W4QG" <W4QG@xxxxxxxxxx>
To: <collins@xxxxxxxxxxxxx>
Sent: Thursday, July 08, 2004 7:49 PM
Subject: {Collins} Help! Newbie restoring a pair of gold dust twins


> Hello All,
> Excuse the long post. This is my first attempt at restoring
> any vintage equipment and I could use some advice.
>
> I just purchased a pair of gold dust twins.
> I think I got a pretty good deal, $1000 for both.
> That's the good news....
>
> Here is the rest of the story:
> I bought these from a another ham who purchased
> them from the wife of a SK who was the original owner.
> (who knows what he paid for them from the SK's wife but I'd bet
> it was next to nothing)  He didn't do anything with them except run
> a damp cloth over them.
>
> The 75A-4 is missing a couple of tubes (5Y3GT and 6AL5) and according to
> the fellow I bought them from the receiver was believed to be not working
> by the wife of the SK. It appears to have had a modification around V22,
> There is a pot hanging out from the chassis. There is also a mod on V3,
> a socket adaptor has been cut in and a cap is hanging off of it.
> The paint is fair at best. Lots of small chips all over the enclosure -
none
> or very few on the face. Has CW and SSB filters. It still has the original
power cord.
>
> The KWS-1 is supposed to be working or at least it was the last time the
> SK used it - about 10 years ago. The KWS-1's RF deck appears to be in good
> shape besides for the paint. The paint is pretty rough, front
> face is nice except for around the lid - many many small chips on the
enclosure.
> There is a large cap from V102 to ground. It is just hanging there. Pretty
sloppy...
> The audio gain knob is not original. No blower hose. The power supply
seems
> to have several mods. Paint is rough. Missing F501 and F502 fuses.
> Also missing V506 (OB2) and V505 (12AX7). V509 (6A57-G) has been pulled
and
> has a jumper wire attached between two receptacles on the socket. V503
(5Y3GT)
> has been pulled and two wires are running to some resistors (also just
hanging there)
> Looks like another wire is just hanging there not attached to anything.
Apparently the
> power supply has been converted to a solid state rectifier V501 and V502
(886A's)
> have been pulled and replaced with diode rectifiers by Solitron Devices
Corp.
> Looks like the door has the original key. There are many holes along the
front sides
> of the enclosure. Is there supposed to be trim there or something??? Is
anyone familiar
> with these modifications? If so are they preferred to the original design?
> The modification around V503 looks highly suspect.....
>
> What are my options on the hose?
>
> I have read about the cap replacements in the KWS-1, any similar issues
with the
> 75A-4? ( I am planning on tackling the 75A-4 first....) Any advice on
bringing up the 75A-4
> after being dead for 10+ years??? I wish I had a big variac... I would
assume it would be a
> good idea to replace the 2 prong power cord with a three before doing
anything???
> I am planning on pulling the chassis and giving it a through cleaning.
Then scrubbing
> the enclosure with some mild detergent and water.  In have checked the
reflector archives
> on the painting issue. Anyone have any recommendations?
>
> I also bought a ITT R-390A ($150), I've done some checking around on that
one, I can't
> find any mention of it anywhere. Any ideas?
>
> Thanks to all.
>
> 73,
>
> Paul W4QG
>
>
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http://www.collinsradio.org
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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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