The AM Forum

I managed to get my craigslist SX-28 home.  I had my brother buy it and I had to go pick it up. 

It looks to be all there and has the matching pm-23 speaker.

It is dirty of course and there is some corrosion.  I will recap it first I suppose.  ( I have recapped an SX-42 and so am familiar with that pain)  I am very interested in not introducing problems as I go, so should I recap it as is, without doing any cleaning?  Then power up and see what I have?

The dials have tiny spots on them that look almost like mold.  Has anyone seen this?  I know the dial markings are very fragile........


Thanks

Rich

Hi Rich.....There is a tutorial on recapping the SX-28 somewhere on the web...I used it when I recapped one for another Ham...It isn't hard, but it does take some time...I would blow the dust out and remove the panel (If it is to be refinished) and then go to recapping...kinda  clean it up as you go along with the capping process...you know, clean the areas whilst you are in there...when the capping is complete...clean the stuff that's left....Good Luck...Steve

Thanks Steve.  That sounds like a good plan.  I bet this is the tutorial:

http://antiqueradio.org/halli12.htm

Step by step, what could be easier?  ;-)

Rich

I give my radios a bath before doing anything else.

Why have a stinky, moldy, dusty wreck in your shack, and your nose buried in it for weeks or months?  Achoo!

Loading one old relic into another.  Note the hernia grimace.

Rich

Now you need an antenna on that plane  like the F4 Helcats had Rich!!

Too bad I sold the ART-13!  Would've probably put me over max gross weight.......

Rich

Yep.  That plane will never blow away with an SX-28 for a tie-down!  :)

R,

Ya don't need no Maytag.....  Ya need a Beasteley 610 to go with yeer SX28.

FWIW, get yourself/or use a digital camera. Its the berries for working on something like the '28. You still can make wiring diagrams when you get into the Evil coil compartments. There is a mill manual online for this thing. www.cryptomuseum.com/df/sx28/files/tm11-874.pdf
I wish I had it before I went inside. When You get inside, Pay close attention to the little brass colored washers on the band switch. I didn't, and now I can't figure where they go.

How old is this Queen??    <http://www.radioblvd.com/SX28Notes.html>

This thing has beautiful audio.


klc

Don't try washing the dials with anything.  Hallicrafters used water soluble paint on some of their radio dials and it will wash off!  Ask me how I know!!! ;D

KLC  yer link doesn't work  try this:

http://www.cryptomuseum.com/df/sx28/files/tm11-874.pdf (http://www.cryptomuseum.com/df/sx28/files/tm11-874.pdf)

The quality of the manual was too good not to post this

Al

A,

Thanks..... I got the > stuck on to it.

klc

I've done a couple of these beasts and here are some suggestions/observations:

1. The military manual is far better than the Hallicrafters manual. You can also get the military manual on BAMA. Phil Nelson's article, which you have already found, is excellent.

2. Is yours an SX-28 or an SX-28A? There are significant differences in the RF deck and the SX-28A is slightly easier to recap. There is a military manual for each model.  

3. The filter caps are a bit tricky. If I remember correctly (which I don't always do), there are some caps with different voltage ratings in the same can. Thus, you have to carefully trace the wiring from the filter cap cans so you know what's what. Also, plan out your terminal strips etc. ahead of time so the replacement filter caps don't look like a rat's nest. (Ask me how I know this). To the best of my knowledge, no one makes reproduction filter-cap cans for this model.

4. If you're tempted to fire it up after replacing the filter caps, you should wait until you've also replaced the two coupling caps to the 2nd AF.

5. Radio Daze sells reproduction dials for the SX-28.

6. If you don't want to diassemble the entire RF deck, you can probably reach and replace all the paper caps, except for those in the first RF section, without diassembly. It takes somewhat less work to disassemble the RF deck if all you need to do is reach the 1st RF section. (I am, of course, referring to the RF deck for an SX-28, not an SX-28A).

7. If you want to diassemble the entire RF deck, it's not as bad as it sounds. The most important thing is to get a really good Phillips screwdriver to remove the screws securing the side panels of the RF deck. Those screws are tough to reach and it looks as if it would be very easy to strip them.

8. For cosmetics, carefully cleaning and polishing all the knobs makes an unbelievable difference in appearance. The same holds true for cleaning and polishing the bezels and dial glass. For some reason, this seems to make more of a difference with an SX-28 than with other models. I believe that I used a polish that the car guys use to shine up plastic headlight covers.

Also having done both a 28 and a 28A, agree on the military manual is good.  Also the W7FG manual is good if it still available (I understand he is SK).  IIRC you need to remove one or two of the shafts to get at the RF sections.  To do this I think you need to remove the face plate too. 

But the 28 is every bit worth the effort.  Also the 28 and the 42 tended to eat output xformers.  So watch out for that.

Good luck.

Peter

Thank you all for the good advice.  I will be referring back to this thread often.

The serial number is 125540, looks like that is 1941?

Rich

If you go though the trouble to pull the
Bandswithch out, to recap, you should also replace all
The resistors. I found just about every one was way
Out of tolerance, high in value.

GL nice rx!

wondering what the consensus is as far as the resistor of choice for RF use to replace the old 1 watt+ carbon comps?? Or the 1/2 watt ones??

                     _-_-

This is interesting as some resistors that look like traditional carbons were said to be inductive due to newer manufacturing methods, meaning a spiral track, maybe not really carbon. More of interest to those drawing from junkbox stores of otherwise unknown NOS resistors.