The AM Forum

Greetings to all

As if getting the BC-1H carted home and prepped for the Winter conversion project wasn't enough, this working near junker was offered to me for the sum of 90 dollars. I couldn't resist and in the frame of mind to keep it amongst the West Coast AMI fraternity, I decided it's a good candidate to restore back to it's former glory. The article here, http://www.hammarlund.info/SP600svc.htm
is a very well written piece that illustrates just how easy it can be to make this a reality.
But first, the front panel had to be removed. It was hand painted with globbed on grey paint with computer printed labels. The pictures illustrate this completely.
At this time, I am in the process of obtaining a gross of custom made STK Polyester 600 volt caps that I use in the custom order guitar amplifiers that I build. The dreaded BBOD's (Black Beauty Caps) will all be replaced. I will also deal with the bathtub caps. For now, you can see the progress I have made in removing the old paint. It reveals a lot of scratches in the faceplate which is no big deal. I will use Automotive body work techniques to fix the surface and prepare for primer and paint. For now, here is a hint for those of you who have had trouble removing the knobs such as this one here, and is WHY the faceplate was painted while the knobs were attached! I removed the hex screws from the knobs that would not come off the shafts. I then took a can of Graphite lock lubricant and sprayed it into the thread holes. I then used a twisting back and forth motion while pulling the knob and holding the shaft. Of course, this revealed why it happened in the first place: Set screws not being tensioned properly, thus allowing the screws to chaff on the shafts causing burrs. This will be remedied by resurfacing the shafts and the inner race of the knobs.
I will update as I progress, but the fun of making the radio work nice is further enhanced by making it look new again. It will be fun.
Thanks!
Billy N6YW

Billy:

    Here's another very good article on the SP-600s.
http://www.radioblvd.com/sp600_rebuild.htm

    Andy Moorer's site is also a valuable resource:
http://www.jamminpower.com/main/sp600.html

                 Joe Connor

Joe, thank you.
I have read those pages completely. Both are very good treatments. Henry Rogers WA7YBS, is one of our national treasures. His painstaking research and devotion to detail is unmatched as far as I know, over a very broad spectrum of equipment. We are fortunate to have access to the works of some very dedicated people in this field.
73 de Billy N6YW

Okay
I got around to purchasing the correct grades of sanding paper, primer and paint.
One last round of spot paint remover, cleaning and then a good sanding session using
#400 grit wet dry paper. This helped to flatten the surface without removing too much
material as I do not want to lose the depth of the engraving.
My best friend in dealing with the numerous scratches on the face plate: Bondo brand
glazing putty compound. This stuff is amazing. I have used it for years with excellent results.
It has a "capillary" action where it fills in the tiniest of abrasions completely. When I sand
it down, it will give the primer a better chance of adhering and hide the imperfections.
The first coat of primer will be sanded down in order to flatten and level the surface for the final
primer coat. I have to keep the coats as thin as possible in order for the top coat to lay down
flat and without too much coverage. This balancing act is crucial because if I use too much paint,
getting the lettering to "read" nice and sharp without rounding off the characters definition will be
hard to get right when I go to fill in with the white lettering paint.
I am not too caught up on these micro details, but I must impart some specific approaches to
getting excellent results in order for this article to have some relevance.
I am adding some photos of the current state of the project so you can see what I mean.

Greets again...
I made good progress today. The fill work made a big difference in preparation for the first primer coat.
After the filler had dried, I rough sanded with 220 dry paper, and then wet sanded the entire face with 600 grit. Viola! Smooth as silk and even though you can still see the scratches, you cannot feel them.
The first primer coat went on flat and perfect. A couple of defects occurred with the primer spitting a
little here and there. It happens. Wait for it to dry over night before I wet sand to level it out.
This is the crucial step because at that point, the coat has to be thin and uniform. I will then wet sand again using #1000 grit  paper and allow to dry in the mid day sun... a free oven because it will be in the 80's
tomorrow! It took an hour to remove the paint on the tuning bezels which revealed straight paint to brass,
no primer back then. They cleaned up very nice and are now also primered.
See the photos that follow.
I am conflicted about the top coat color. I bought what I felt was a good match, a Krylon gloss enamel.
But, I have some left over Collins S-Line cabinet paint #180, that looks like it would be a good choice.
What would you do? They both would look great.

Additional pics here:

And, yet some more:

After getting very frustrated with a BC-779 panel that I have been working on over in another thread, I would have done mine differently than I did had I to do it over again.

My panel was far from pristine, is steel, plated with apparently nickel. Had dings, pinholes and other scratches.

Long story short next time I do one of these, I intend to lightly acid etch the panel before shooting the primer, and/or using one of these newer "self-etching" primers. The reason being that I ended up with flaws that did not get properly fixed with spot filler primer, or Bondo glazing putty (which I have no use for - couldn't find anything better on the day I was looking).

What was the stuff you smeared on?

Hope ur panel paint adventure turns out better than mine has - I'm going to live with the imperfections. No desire to repeat that process right now.

If you look at my post, you'll see a very interesting paint scheme on an SP-600 that was the inspiration for mine.

Urs is looking good! Wish I had an SP-600 myself.

                       _-_-bear

Looks like you'll have a beautiful band cruiser once it's done, Billy. Nothing else quite compares to the feel of a properly adjusted SP-600 tuning knob. Truly the opposite of tuning the venerable R-390 series.

Two bits of advice that were passed to me years ago (remedying problems in both cases):

- Check the voltage tap on the power transformer and make sure it's adjust above your line voltage. I can't recall now but I think it goes from 117 to 125 or 130 vac with numerous choices above and below those values. My first 600 wandered all over the place and I bought into the 'Hammarlunds are unstable junk' theory until Les Locklear reminded me to check the tap. Sure enough, it was set right on the hairy edge and changing it up a notch made all the difference in the world. It was like having a new receiver.

- After cleaning the gear train be VERY careful and stingy when you re-lube it. A little too much oil is all it takes to cause the tuning to slip. Might not show up immediately but it will eventually migrate out to areas you don't want it to be in.

Looking forward to the finished product.

Todd
Thank you for the encouragement and comments.
The project was split into two fragments for logistical reasons. I had to wait for the paint on the panel
to cure for a couple of days, and then I baked it to make sure it laid down flat and hard. This paid big
dividends. When I wet sanded with the initial 600 grit paper, I didn't have to remove as much material.
This is a BIG plus because having to go back and do spot jobs with enamel really sucks. Lacquer is easier because it "melts" back into the finish.
So check out the panel folks. The lettering is nearly complete with just some minor touch up and a final buff out, then wax. When doing the lettering, a squeegee is paramount and it allows less wet sanding to remove excess spill over. Getting rid of the orange peel and fish eyes that occur is the most tedious part of this
project. I did not use a compressor paint system, just spray cans of good quality. Technique and feel for proper depth and spray pattern is essential to getting uniform results.
The second part of the project has been re-capping the entire radio which requires a lot dis-assembly that isn't hard but requires patience and understanding. Planning your work in advance helps a lot.
I found that 25% of the caps were cracked and had significant failure. How it had no burned resistors is beyond me. I know this much, even without an alignment (it was a working unit) I know it will release a
lot of signals like never before. That moment of truth will be astounding, barring any mistakes or overlooked issues that arise.
I am stoked to get the results so far. It seems that the work has been worth it and man what a difference.
More to follow, so stay tuned.

I want to apologize for my friend Billy's reference to the Southern California weather. I'm sure he meant nothing by it.

-- Jon

PS: I notice 6 above in my home state of Montana and a -7 in Wyoming.
PS2: Panel turned out gorgeous, don't you think?

Jon
Why thank you Sir. The fades are producing some wild propagation tonight. Should be an interesting net.

Bear...
It's the Bondo brand filler putty. For future reference, go to an Artists supply outlet, and buy a set of
"Palette knives" that are used in painting. They are thin and flexible and do a fine job of applying the putty.
They also allow you to trim the excess material off so to minimize sanding down. Be sure to use a fine tipped Dental tool to scrape out any dirt or funk that might be collected in the scratch or gouge. This will allow the putty to bite and adhere better. Do this before you prime the face plate.
The idea of etching the plating is good if you have a lot of pitting and rust damage. Iron Oxide treatment can be good for this sort of thing from what have been told. It stops rust in it's tracks and will not let it continue it's growth.
73 de Billy N6YW

Update:
It's been awhile since I posted anything on the SP-600 restoration project.
Now that the holidays are officially over, I began the final phase of finishing the recapping
of the SP-600, and did some of the final finishing of the faceplate and bezels recently before
the WX got cold.
I must say, that the SP-600 is without a doubt, one of the biggest pain in scrot to fully restore.
The amount of work needed to remove structural parts, including the crystal select box just to change
one bad paper cap took me over 2 hours. No complaining here, just stating the facts.
The turret and associated circuitry was time consuming but very interesting and challenging.
Using my 8mp camera in my phone has been one of the best documentation tools too and paid it's
weight in gold for preventing mistakes, especially reading the archaic cloth wiring codes of the period.
Double checking your work has never been easier and proves beyond a doubt as to why we should always photograph our work before we disassemble anything.
I am now done with the most difficult parts of the R&R of the caps. The transformer cans are the final
chapter of this journey... 50+ caps to replace in the beast. By the time I am done with this restoration I am estimating it will have taken in excess of 80 hours including refinishing the paint and engraving of the faceplate. Hell, I spent 2 hours removing the scratches and buffing the lenses of the tuning bezels alone.
Again, no complaints because this is a master work project where time is not as important as the final result is concerned. When this piece is done, it will reflect the work involved. I will be firing it up for the first time
this weekend and I cannot hold back my curiosity of how well it will perform compared to before.
For example, when I bought it I was told it worked "fine", meaning okay. After I removed two dozen Black Beauties alone that had cracked open, and a couple of discolored resistors, I am positive it will torpedo signals out of the speaker like never before.
I will need some advice on alignment to really get it right, but that's another thing for another day.
Firing up the smoke test this weekend will be good enough for right now.
73 de Billy N6YW

  Billy,

       You will love your SP-600. A machinist buddy of mine "Created"
this tool for me. The "Negative" screw driver on a long shaft is real
handy for getting to those variables inside the turret.  Being metal
it takes a couple touches to get it right.

73

/Dan

Thanks for the pictures of the alignment tool.
We shall see this weekend, maybe even tonight if it passes the smoke test.
The cap job is officially done. Because it was a working radio when I bought it,
without mistakes made on my part, it should fire up and receive signals.
I can hope anyway. Wish me luck, a report will follow.
73 de Billy N6YW

    8) It Lives! 8)
The smoke test revealed two burned 1K resistors in the RF strip which required my having to remove it again. Also, found a fault in the filament leg going to the RF strip, which explained why I had no candles. Dead nuts on 10 Mhz WWV and stable as a rock.
It will need a tweak and peak but for now I am stoked that all of the work I put into this rig
has paid off. I will post photos later of the finished project. I still need to finish sand the tuning bezels and mount them to the faceplate, detail the knobs and button up some minor stuff.
By the way, if you want to "Polish your Knobs" try using Meguires Plast-X polish that is used for polishing the plastic lens on your car headlamps. It's good for finishing off the look.
More to come.
 :)

What a treat...
And, a monumental amount of effort. All of the details involving this level of restoration is quite a task. Even remounting the faceplate is a series of tasks that require attention to detail and
corrective measures. I now fully realize why high level restorations bring the kind of dollars
as seen these days. While I don't pretend to assume the title of a master restoration specialist, I am certainly in the ballpark of being able to comment with some well learned facts.
Planning, tools and technique. Know your stuff and just when you think you know it all, there will be some instances that put you back in your place. It takes time and lots of it but man what a thrill to figure this stuff out and make it work. Look at the before and after photos and you can see for yourself. I look forward to advancing the skill involved with this type of restoration work. These become our own legacy items that we pass down to others to enjoy, and I feel in the end game, that's what really matters. Meanwhile, I am going to love running this beast through it's paces!

Outstanding workmanship!!

Hard to believe it's the same radio.

I have a SP-200 (BC-779 then BC-1004) that had a gray panel with a lot of paint gone.  I replaced the panel with a black wrinkle Super Pro panel.  Even that panel is far from perfect.

You did a great job.

Fred

Here's a few shots of the button up and the new stainless steel hardware. I was bummed I couldn't find the correct flat head style cap screws, so I had to settle for Phillips instead.
Was listening to some QSO's on 10 Meter AM for a while this morning. It sounded great.
Further testing in CW mode confirms I have a bad BFO. It's fixed and will not change frequency, so I have some more work to do. I will not be using this receiver for that purpose for the most part, mainly AM. It really sounds terrific. So pleased.
The knobs came out very nice but it took 2 hours of solid elbow grease to get them to shine.
Use rubber gloves when you do! Your fingers will thank you.

Here are some fun photos.
Enjoy.

Thanks to everyone who participated in this thread. It's been a joy to share in the project with you. I hope this may be a stimulus for those who procrastinate about that old project languishing on the self or the end of the bench, to get started and see it through to completion.
Long live Boat Anchors!
73 de Billy N6YW

Thank You for sharing your very inspiring project, and what a Beautiful Jewel it has become!
I have an early model JX21 (S/N 16315) sitting on the shelf next to several Hallicrafters R274/FRR's.
Once I get settled in from moving the QTH and construction of the Heavy Metal Transmitter is finished, I plan on devoting my attention to the receivers.
I enjoyed your thread!

B,

That is some very nice work. That dahling looks marvelous.

But I worry for you. The rcvr is in front of, and over COLLINS equipment. Please be carefull.The Collinestas are every where.


klc

I WAS a Collinista at one time, but that was on a planet a long time ago..
What ever works I say, and for AM, I have yet to find a Collins outside of my R-390
that compares to an SP-600... for AM. My 51J-4 for CW was awesome and smacked
the scrot out of my other SP-600. Just for comparison sake mind you. :)

Get a 9.4 kc filter and connect the diode load to a hi-fi amp, and your 51J-4 will sound as good as your SP-600, probably better. Trust me, I've had both.

And if you want to go super hi-fi, put an RC coupler in one of the filter slots. Now you can have 13/14 kc bandwidth with gentle skirts, just like the SP.

Nice reply. I sold my 51J-4 last year after I decided I didn't really need it anymore.
Perhaps if I find another one that is worthy of getting right, I will. My last example was not a very good one and had factory made problems I didn't want to deal with. I have owned 3 of them over the years. For AM, they are not in the same class as the R-390 in my experience but they do have more going on for CW.
Anyway, the SP-600 has been going all day and it is amazingly stable and SWEET!

That was not to take anything away from the SP-600. They can sound fantastic. I had a very nice one. The big tuning knob made it a great band cruiser. Over time it got pushed aside as I used the 51J and the Super Pro 400 more. I think Todd, KA1KAQ has it now.

Congrats on your skillful resto.

Thank you. :)
Receivers are interesting for so many reasons. My collection is modest compared to most. I have sold off much of my collection due to my changing needs and lacking interest in having the "Best" or "Most" of the crop. I currently own what I consider to be the finest of the era with the exception of a couple that are out of my reach. I sure wish I still had the Racal RA-17L but I didn't use it often enough to warrant the rack space and while it's perhaps one of the best ever made, it never became my go to receiver. The SP-600 project came about from my remorse for having sold my other one, and the fact that it only cost me 90 dollars... delivered! It may not have the selectivity and CW capabilities of the 51J-4 but for band cruising, it's hard to beat and is just a blast to use. It has a vibe about it. On the other hand, the "J" had a dull audio quality to it that I never liked unless I bypassed the awful audio circuit and drove the signal into an audio mixer, then it sounded very nice. I did the same with one of my 75A-4's and that made a huge difference. This 600 will likely be coupled with the Johnson Ranger and parked on 10 meters where it hears very well. Maybe one day when my utter contempt for the CCA wears off, I might have some ambition to get another J or at the very least, a 75A-3. Both are very great receivers. For now, the 600, R-390, AR-88 & HRO 5TA1 are plenty. The NC-300 also does a fine job coupled with the GK-500-C. Life is good here.

I've owned two 32Vs, an R-388, a 75A, and two 51J-4s. Still have a 32V, 75A and 51J-4. The CCA never bothered me. I wouldn't even know it existed other than when someone else mentions the name. As the song goes, I ain't here to judge or please.....  :)

Well stated. My 32V-3 & 75A-1 was a fun station. I kept it parked on 40 meters.
I was impressed with one feature of the 75A-1 in that I could hear stations way down in the
noise and still have intelligibility. Mine seemed to have a certain "it" that no other receiver I have ever owned. When I decided to pair down my collection, I sold those off.
BTW, is it me, or does the 32V weigh more than any other transmitter of it's size?
A brutal beast to move.

At 105 lbs it's a gut buster

Here it was as of a year ago. Brutal to lift but it's with a friend now who loves it and is now "his burden" to lift.  ;D