The AM Forum

Good one  I liked the one I had . Someone else liked it more .There is only one "original" finish.  ;)

The fellow who took over the panel painting and screening from Lynn N0ALO (?) was here in NC, but apparently the biz has disappeared. The panel should be easy enough to do provided you get a good silkscreen made up first.

Hank Arney KN6DI and (I think) Gary Harmon who's K5 call escapes me at the moment made up that batch of bezels some years back. Not 'exact' as far as all the different radius cuts, but very close (and far better than a warped/cracked example). They used cast aluminum as I recall. No idea if any of those are left, but there might be one or two looking for homes still.

It's been a while since I looked closely at the knobs, can't recall if any are specific to that radio only as far as the lettered skirts go. Knowing Hallicrafters, probably not. 'JN has one and is a good one to ask about details.

Good luck with it.

Don't carelessly turn the SX-88 upside down on the bench with the case off because you will damage one of the IF transformers, there are a number of SX-88 receivers that suffered this fate.

You will find a number of black beauty caps inside.  The only really difficult area is the 2nd conversion oscillator chassis.  You will need to unsolder several difficult to reach wires in order to remove this sub-chassis, mark the locations carefully before removal.  In addition to the caps you will almost surely find a number of far out of spec resistors.

The only oddball problem with mine was a lead to one RF coil that was passed through the coil terminal, marked with red inspection paint, but never soldered. 

I don't know of any current source for the belt.  K9RJ (SK) had a run produced but those are long gone.  I would love to find a spare.  The receiver will work fine without it but the light shadow mask will no longer follow the band switch.

It is an enjoyable receiver once restored and mine has been very reliable.  It is paired with a Ranger/Desk KW and the Pierson KP-81 below is paired with a Viking 500.  I looked for a SX-88 for many years before finding one.  Mine is one of four originally owned by Bob Denniston who put Clipperton Island on the air in 1954.

Hello Gary,
I agree,
Anyone have a mint NOS SX-88 Front panel?  ;D

Len,

If you find a source for the belt please let me know!  I am a bit nervous when I change bands :)  There was an ER article that talked about making a replacement from piano wire, any port in a storm.

It has been several years since I went through my SX-88 but if you have any questions when you get into yours I will try to address them.   I made a couple of wooden "legs" to support my SX-88 when it was upside down. 

If you don't already have a signal generator that goes down to 50 Khz, start looking for one.  The final IF alignment is critical for best performance and you need a 50 Khz. generator to do it right.  If you have an audio frequency generator see how high it goes, before I bought the external down converter for my HP-8640B I used my very vintage HP audio oscillator which covered up to 200 Khz. on the high end.

I echo Rodger's comments.  Don't put the receiver on its left side, either, because you will be sure to break the IF transformers.

Per the belt, at a surplus store in Minneapolis I found a box of cogged belts that were surplus from copiers or something.  I picked out a few likely suspects and lo and behold one was the right tooth pitch but was about 1/2" too short and too wide.  The width issue was solved by slicing it down its middle with a razor blade; the length issue resolved by loosening all the idlers and shafts and re-tightening them with the belt in place.  I now have a spare, too  ;D

The hunt for knobs will certainly be interesting!  Good luck, Len!

I hear you, the dividing line between preserve and restore.They don't have to be mint to work well.  ;)
 Different folks place different weights on the two. I used to want to take everything back to day one. Lately I have taken more interest in getting the function into top shape whilst cleaning up and preserving as much of the original finish as possible. Different philosophies for everyone. I get a bigger charge out of a well preserved original than anything that even hints of refinishing. In the end , the owner must decide  .In too many cases the previous owners may have already made a big enough mess  that a refinishing job is about the only option. Looks like you are there ! Either way, the SX-88 is a real fine catch, congrats.
 You may find that a good RP shop can make up a very nice plastic bezel for you.  You could also have a 3D working model or pattern made and hand lay a good looking fiberglass replacement. In the concept car business we often made parts like this with fibreglass.  The glass of course is far more stable than the Halliplastic and should hold up for years.
  

Bob W0YVA does HT-20 front panels.   Maybe he also refurbs SX-88s.  Might not hurt to ask.  You have to get it separate from the bezel.  I see your bezel warped.  I had that happen on my HT-20.  For now I'm just going to run it without the bezel as mine is so warped and cracked it actually looks better without it.  Unfortunately the SX-88 bezel goes all the way across the front.   :-[  I learned from Rodger that if you encounter a stuck set screw on a knob, drop a bit of oil down the hole and let it set for a day.  If your f.p. isn't too bad maybe you don't have to have it redone.  On the HT-20 here the paint was peeling off and it looked like hell.  One other thing, somewhere on this site there's instructions by JN on how to redo the Hallicrafters gray/black cabinets. 

I completely agree!
There is nothing better than the original deep dark looking Patina from the original finish.
Yup....With this rig, the only option is a complete cosmetic overhaul...
Interesting idea on the fiberglass replacement, I would still need a complete original panel for the artwork?
When I look at the pictures, it appears that the panel maybe original from the cut out pattern for the 5 switches
in the center...

I should be able to verify this after it arrives tomorrow....

Len

Hallicrafters gray/black cabinets:  Semi gloss rustoleum for the black part.  The cabinet top can be painted with a GMC truck DupliColor pewter or silver gray (can't remember which I used now) which is a very close match.  Spray bomb silver is way too bright.  The DupliColor's tone is almost exact but it of course has little flakes in it that the original doesn't have, so a close eye can tell the difference.

Key to success is a lot of prep work.  Sand it well, make sure all scratches are sanded smooth.  Wash a couple times using mild detergent.  Use a tack rag, then prime with gray.  Sand with wet 400 grit.  Clean.  Tack rag.  Another coat of primer.  Sand (wet 600 grit this time), clean, tack rag.  If it's smooth as a baby's bottom by this time, do the black (or silver gray, depending upon the piece you're painting).  Sand, clean, tack rag, then the final coat. 

If it'll fit in your oven, bake it at 180 degrees between coats.  There'll be hell to pay with the war department but the finish will be good and tough.

Definitely not an original finished panel if you're still wondering on that, Len. Looks like someone had it anodized and applied some P-Touch labels to a few controls. The rest are blank, labels were on the knob skirts for many.

Should be a typical Halli gray panel with white lettering and trim around the switches. Maybe Rodger can give you a good close up shot of his to give you a good idea where to start.

I'd say if you get a replacement bezel and get the front panel repainted, that would be more than half the battle. Knobs will be a challenge, but some at least may well be shared with a few other sets like the SX-62, SX-42, etc. that also used the labeled aluminum skirts. You've got the two main tuning knobs which is a big plus, they're probably the most difficult to find. Halli used them on the SX-73 and R-649, maybe a couple others. I have no idea if any of the small knobs were specific to the 88 only, though I doubt it.

Johnny is right on the money for the black color. If you can't find the silver he suggests, Rustoleum had a good match for the silver cabinet cover too. Can't remember the name/number right now. Seems like it was Dull Aluminum or something along those lines. Not too bright, no shiny bits.

Looks like you've got a excellent foundation for a rebuild. As was mentioned, it may not end up being perfect 'collector quality', but you should come out of it with a nice looking and working set when all is said and done.

The gold lid is a hammy hambone addition, too.  All Hallicrafters cabinets in that style had basically the same paint - black cabinet with a silver lid.  It's just plain ol' steel underneath.

That cabinet is unique to the SX-88 though, it's deeper than any other Hallicrafters cabinet.

This may or may not be helpful on the bezel, but since it looks to only be distorted, you may be able to straighten it if you're very careful.

I did a straightening job on a bezel or "hood, if you will", for a NC-270 once. With a lot of patience, and luck, I got it back straight as an arrow. The main thing to remember is work VERY slowly, over days; weeks, if necessary. Crank a LITTLE pressure, let it stand a day, take it out and re-check it. You'll need a good bench vise and a lot of different shim materials in different sizes, shapes, and material. Don't forget that a little heat in various temps/durations can really help also. The key is VERY SLOW! Also, if it does manage to crack, remember those Wonder Rods they used to advertise on tv that would braze anything? The only 2 times I have seen those actually used, they did work. Once more, VERY SLOWLY.

As it stands, you don't have anything to lose, but don't take that mindset when you start. Think of it as being the last one available. If it is really crappy pot metal, it may be a fruitless exercise, but what the heck?

73, Phil   

 

The bandwidth knob (goes from 250 cycles to 10 KC for the SX-88) is unique to this receiver as is the actual frequency band around the band switch knob but the knob style itself is common to other Halli gear.  Other knobs are common to a lot of Halli gear and you can probably live with a close match from another receiver for the bandwidth knob. 

As long as your belt doesn't break, you won't need the frequency markings on the band switch knob :)

Rodger's input on the band switch knob is great, because it's the same knob used on the SX-42, HT-32/33 and maybe a couple others. I just sold one along with a full set of SX-42 knobs (probably some of the ones you need!) last fall. Held onto them for years, no one needed them, so off to the 'Bay they went.

You'd need to clean and most likely repaint the skirt, then either do an excellent job of re-lettering with dry transfers or maybe make a clear decal you could wrap around the skirt. Ask Bob about this, maybe he already did his over. No need to re-invent the wheel.

Or as Rodger says, just find one with good paint from a SX-42 and stuff it on. Close enough.

I bet Gary will turn up a bezel for you.

That "gold anodized" panel may be "Alodine" which is a conversion coating suitable for taking paint. I forget at the moment what the generic coating is called, another CRS moment...

That "gold anodized" panel may be "Alodine" which is a conversion coating suitable for taking paint. I forget at the moment what the generic coating is called, another CRS moment...

Len,

It looks like this should turn into a very nice SX-88 when you are through.  I would get the panel and all of the electronic and mechanical problems addressed and then worry about the bezel.

 It has been a very long day but I will try to comment on a possible repair for the pointer drive tomorrow, I wouldn't put a lot of trust in any complex explanations I write tonight.  Someone else may chime in before tomorrow.

One other caution:  I had no problems with seized adjusting hardware with any of the IF transformer adjustments with my SX-88 and you probably will not with yours.  But if you do, proceed with extreme caution as the low IF transformers in the SX-88 are exclusive to this receiver so another SX-88 is the only source for a proper spare.  Although it would limp along with a replacement transformer out of another one of the Halli 50 KC low IF receivers (SX-96, 100, 101, 111, 115, 117) the SX-88 IF transformers have significantly higher Q and the difference is evident in a side by side comparison with the later family members. 

Wowsers, Len. It actually looks to be in pretty clean shape overall. And someone has re-capped it already, though you might want to re-check and redress the work.

Basically, once Bob repaints the panel for you and you get the cabinet done, all you'll need to deal with is the bezel and knobs, bolt-on parts. Not bad.

I have a bad feeling you won't have much luck straightening that bezel. Even if you could get the main sag out of it, the other waves would still be obvious. Though it might be a bit on the costly side, if you can't get one of the replacement bezels through Gary, perhaps you could get one machined locally. In fact, it might be an excellent project for a local shop class to undertake.

Keep us posted on your progress. And watch ebay for SX-42 knobs or a beater parts set as well as putting out the word here and elsewhere.

Alodine (a conversion coating process similar to Iridite) leaves a gold tone finish on aluminum. "Metal-Prep" often leaves a yellowish looking phosphate coating on steel . Both are good substrates for paint.  There are a few replacements for cadmium plating now in use for steel finishing that leave a yellowish sheen. Zinc Dichromate is but one of the Cad plate alternatives.
 "Aircraft Spruce and Specialty" handles many products for finishing and preserving metals along with great metalworking  tools and supplies. A request will bring a catalog.
 For the rattle can painters; An alternative to flat black Rustoleum paint is Krylon "Chalkboard" black. Not as chalky as one would think. A very durable semi-flat furface.

Thanks much for the reply....
I am awaiting you comment on repair of the pointer drive.  Upon close examination of the pointer cam, the silicone used will first
have to be completely removed. That should hopefully peel off.
Regarding the 2 IF cans on the left back side, Is the soldering method the best at repair? Basically soldering the rivet to the actual can itself? If so, Would applying heat from the solder gun possibly damage the IF can in anyway?

If you could, send me some good closeup shots of the pointer drive so that I am sure I understand exactly how it is broken.  

It will take a fair amount of heat and there is no other source of these transformers so there is a definite risk with soldering.  If it were mine, I would try one of the two part epoxy mixes and make a neat repair with it.  Although JB Weld uses a lot of hyperbole in their advertising it is a pretty good product and I have used it for a number of metal repairs.  I wouldn't trust it to repair a cracked engine block as they claim in the advertising but I am confident it would easily handle the much gentler environment of the SX-88.

I am glad the silicone came off in one piece without taking anything else with it.  The rest should be a simple repair.  One wonders why the person who repaired this didn't do it properly in the first place since it is a fair amount of work to access this part of the receiver. 

Make sure you pair this receiver with a decent speaker to take advantage of its wide bandwidth IF and audio system.  I use a R-42 with mine and it sounds great with good source material. 

I have some additional advertising and other SX-88 related stuff that I will scan for you.  Next week is very busy but after that I will have time to get this stuff to you for your SX-88 collection.

Len,

It looks like a  very good repair and the IF transformer repair should be even easier.  You are going to have a great set of before and after restoration photos when you finish this project.

Any suggestions to remove the black spray paint that was used to paint the 5 switch levers on the front?

Yup - Q-tips and MEK from the paint section of your local home store (except in California, I suspect).  Be sure to do it in a well ventilated area.  MEK isn't the worst of the solvents from a health standpoint, but it is potentially more intrusive than acetone, for example.

Also, I forgot to add, JUST IN CASE there is a possibility, make sure it's not made out of magnesium BEFORE you add any flame?
 
73, Phil

It depends on what you mean by polish.  See http://amfone.net/Amforum/index.php?topic=24506.msg182212#msg182212 for a wide ranging discussion of the subject.  ;D

  Actually , open flames on magnesium parts are no real problem. Although I seriously doubt this is a magnesium part.

Len,
        I couldn't possibly get to the task in a timely manner due to all other things going on here besides the big task of moving. Looking through your recent posts though, it seems it's in fragile shape and if the others advised you it wouldn't survive, they would know much better than myself because I don't have any first hand knowledge of the rig.

I agree in that you would probably be much better off to have one made from aluminum if a suitable replacement couldn't be located. Even though it is badly disfigured, it would be much better for the existing bezel to be in one piece so that a machinist could more easily get the measurements he needs.

Another thing that came to mind is casting one from resin (better than nothing at this point) which would also present the problem of needing a good donor to make a mold.

Wasn't too sure of the flammability issues of magnesium, just remember the stories I've heard about the old style mag wheels on cars catching fire. Probably just old wive's tales used to embellish old war stories of drag racing.

73, Phil

You will likely find that a vacum bagged epoxy-glass layup is far more stable than most resin materials . Especially with the long spans and thin sections.  A good pattern maker should be able to make up a suitable form if a decent sample is made available. If I had a bezel you would be welcome to borrow it. Sadly I do not. My buddy up in West Branch MI (Ron Hattner, N8UUH)  has one , maybe I can borrow his and get a pattern made up for you. I will try to speak with him this week end.

  Torches aren't a big issue when working mag alloys. We TIG and Oxy-Acetylene work it often. ;)

Congratulations on your recent SX-88 acquisition Len. Whether to restore or not as mentioned earlier in the thread is subject to one's personal views toward historical items but in my opinion the SX-88 should be restored to working order with a good appearance whenever possible. It appears you have a few challenges ahead with your's but basically you have a very good restorable receiver that should yield satisfactory results. I have restored four SX-88s so far and have just recently started on a fifth unit so have accumulated at least some practical experience in the process. I can offer some of the techniques I have found helpful so far.

The bezels were all potmetal with an inconsistent mixture of ingredients so some warped with environmental temperature and humidity changes but many did not. Any attempt to straighten yours will likely result in breakage as decomposed potmetal is very fragile and brittle. Early potmetal was the dross skimmed off the top from refining other metals. I would try to buy the CNC code from Dan Arney and make a few more. A word of caution is possibly in order here though. The original part was a casting and the design included a compound radius inside the picture frame. To accurately duplicate the appearance of the original part by machine you would have to have CNC 5-axis simultaneous capability. Dan's reproduction bezels were run on a 3-axis machining center and while pretty close to the original they do not feature the original part's compound radius in the picture frame inside corners. If you need a bezel they sure beat not having one though and Dan should be recognized for stepping up and making parts available and filling a genuine need.

Paint can be whatever you want it to be but for best appearance results the gray should be a flat gray and the silkscreened nomenclature should be an aged or antique white. You really don't want bright refrigerator white silkscreening on these but that is what most silkscreeners will put on if you don't specify.  

Three of the knobs you need are specific to the SX-88 which are the Band Selector, Response, and Band Width. You could use the SX-42 (or HT-32) Band Selector knob and ignore the nomenclature since it will not match your receiver. The Response and Band Width knobs could be made from  a standard AF/ RF gain knob with a 0-10 skirt with painting and renumbering. All others were used on other Halli models.

It looks like you have the dial pointers fixed already but all they are is brass rods soldered to each side of a brass disc. If the epoxy does not hold you can always solder them later.

Be sure to support the phone jack with a wire tie to the Response control shaft, the leads are solid core and will break away easily moving the chassis around. Not a big deal but saves unnecessary additional work.

This is a receiver that will require extensive recapping if top results are to be realized and you really don't want to disassemble it a second time to revisit things missed during the first attempt. In my experience besides all the plate and screen bypass caps (which are the most critical) you have silver mica tank caps inside each of the 1550/ 2075KC first IF transformers which if left unattended to will likely result in a steady barrage of static crashes and sizzling bacon sounds in the audio. You will also find lots of resistors have drifted far over the high end tolerance range that will need to be replaced. In my estimation an SX-88 receiver will not be ready for alignment unless you have replaced all capacitors in the 1st and 2nd RF stages and 2nd converter deck in addition to all 50KC IF stages and checked and replaced all resistors as necessary.

It is very common to find broken lugs on 50KC IF transformers T-12 and T-13 mounted on the left rear corner of the chassis. Due to the triangular shape of the side brace the chassis will easily roll over and fall before you can catch it when out of the cabinet and stood up on its side. I always remove the side braces anyway and often screw one or both back on backward to use them as temporary chassis stands. If you remove the nuts the IF can will slip off with the coil form left in place but be careful about the clip on top, you don't want to tear the thin bakelite coil form while pulling on the can. You will have to unsolder the lugs anyway to properly recap so you might as well remove the IF transformers anyway. The cans are made of .015 stamped aluminum and .015 aluminum sheet stock is readily available. I always disassemble all IF transformers to check for overheated windings anyway and this is a convenient time to repair any pulled lugs. Straighten the torn aluminum around the lug mounting hole and press flat. Cut a small square of .015 sheet aluminum, punch a hole for the rivet and epoxy to the inside of the can over the affected area, use a C-clamp. When cured I re-rivet the lug to the can but small hardware of the appropriate size would work just as well. Be very careful with those threaded ferrite slugs as they are irreplaceable. Make a proper adjusting tool according to the directions in the instruction manual and don't be tempted to use something that seems to fit. The ferrite on top of the slugs is very thin and will break if the slug is tight and the appropriate tool that fits correctly is not used.

If the previous owner had the 2nd converter sub-chassis off you should see evidence of removed wire leads, there are about 12 of them and access to some is very restricted. Without proper equipment it is difficult to achieve professional looking results removing and reinstalling them and many SX-88s out there right now look like they have obviously been apart.

Regards, Greg

SX-88 Serial #400 currently in process:

http://i104.photobucket.com/albums/m191/wa1kbq/SX%2088%20-%20400/SX88-40023.jpg

http://i104.photobucket.com/albums/m191/wa1kbq/SX%2088%20-%20400/SX88-40027.jpg

Oh by the way,

I am not running to put this all back together yet. So if anybody would like to offer a computerized CNC milling machine and copy the bezel, let me know....

Can you supply me with a place to purchase the proper alignment tool for the IF can adjustment?

I am curious to ask if you have over 100 bench hours in the restoration shown?

What do you use to treat the metal? Is it a step by step process?

The front panel is going to be restored by Bob W0YVA in the near future.

If you find a source for a workable belt please let me know.  Mine is OK now but a spare would sure be nice to have.

Len,

Great perseverance!

Hope you actually listen to the radio and use it after all this painstaking work and time!! Wow.

How about some pix of the unit as it now sits??

                          _-_-bear