Restoring My Scott SLRM

[Michael Lawton]

About a year ago I bought a Scott SLRM off eBay. I got it for a very good price. The shipping cost more than half what the price of the radio itself came to ! Yup, this thing is HEAVY. This thread will document my restoration of the receiver. First some shots of the radio as I received it.

She was not in too bad condition when she arrived. The plastic dial glass was gone, and the power cord was an 18 gauge piece of junk that looked like it came from a 1950s lamp, but otherwise the radio was in nice shape. Happily it came with the correct power inlet and mating connector, so replacing the power cord will be a breeze. Sadly, the radio is missing the special connector that plugs into the antenna jack. Once the external assessment was done, I went on to removing the chassis from the heavy steel cabinet in which it arrived.

The first work I did was replace the plastic dial glass. Happily Robert F, from this site, a friend of mine from Philco Phorum, sent me one he had extra which Mike H from this site had made for him. Replacing the dial cover was not an easy task. It required removing the entire front panel of the radio. First I removed the knobs. These are SERIOUS knobs with two set screws each ! Then there were 8 screws with nuts and lock washers, and one smaller screw holding the front panel to the chassis. Two of the screws with lock washers are real bears to remove since the nuts and lock washers are buried and almost impossible to handle while turning the screw. All the others are fairly straightforward. The smaller screw goes into a standoff and was the simplest of all to remove. Happily none of the jacks or other attachments to the front panel need to be removed. There is enough free length of wire attached to them. Once the panel was off, I removed the bezel for the dial glass from the panel. It is held by 4 small screws. I then removed the dial pointer from the inside of the bezel. It is held in place by a single little screw. Behind the pointer, between it and the bezel body, I found some remains of the original plastic dial glass, all shriveled and brown. There were a few little remains of it also around 4 little brass studs around the edges of the bezel inside which help align the dial glass. I took the new dial glass and began to fit it. I had to drill the 4 holes to go over the studs, and sand the edges of the piece to just fit inside the slight recess for it in the back of the bezel. I sanded the dial pointer smooth, removing the old flaking paint on it, and repainted it white. When it was dry, I fitted the new dial glass into the bezel, and set back the dial pointer to retain it along with its little screw. This is what it looks like all finished...

After that I removed the bottom plate of the chassis, and began my assessment of the radio. I was very happily impressed. I have never seen such a beautifully, and durably built radio since my Navy days. This radio was SERIOUSLY constructed to weather the elements at sea. I have decided to take Robert F's lead and start by just replacing the electrolytics. I will probably measure them and take good pictures of them, and see if Hayseed Hamfest can make me some replicas to use. All the paper condensers one would normally have to replace are hermetically sealed away from the elements in oil filled little metal cans, so they may well be fine for years and years. Here are pictures of the underside of the chassis before I start any work. First is an overall view, then a series of shots going from the electrolytics down that side of the chassis, then up the other side to the front, and finally the middle of the front.

So, that is all the progress so far. I have ordered some parts and am waiting for them to come in. I have also contacted Hayseed Hamfest to see if they can make me custom replacements for the 4 electrolytic condensers along the front of the receiver. I have bought a full set of replacement condensers from them for restoring my National SW-54, and NC-125 radios. They made PERFECT replacements for the 4 wire firecracker in the SW-54, and the can in the NC-125. Fortunately, the parts list in the manual for the SLRM gives quite exact specs for these condensers, with the diameter, length, number of terminals, and so on, which I passed along as well as a JPG of the schematic. I hope they can make the new condensers for me. Stay tuned for more of this continuing adventure.

[Michael Lawton]

I ran through all 4 bands tonight, very slowly scanning through them. The AM broadcast band is MUCH better. I am able to get WSM 650 KC out of Nashville very clearly at night now, and many stations all up and down the band. I do notice that stations from the north don't come in nearly as well as those from the south or east or west. I figure this is because the mountain is masking the signals from that direction. I think the rebuild of the antenna, adding some more height may improve that situation. The second band had stations in the BCB up to about 1.8 MC, then the ham bands. I could not receive CHU on 3.33 MC. (I really do think it is the mountain masking the signal) I did hear one AM religious station up near the top of that band. The next band, 3.4 to 8.8 MC was alive with stations. In the ham bands there was CW and SSB. with the selectivity switch turned to CW, I was easily able to hear them, although I still haven't quite got the hang of getting the SSB to sound as ineligible as I can with my Hammarlund HQ-129-X. There were plenty of AM stations up the dial in the international broadcast bands though to make up for it. WWV came in clearly from Fort Collins, Colorado on 5.00 MC. I was actually able to hear CHU very clearly at 7.335 MC. There were lots of other stations, many in Spanish also. The highest band, I scanned that down from 18.6 MC. There was some CW and SSB up there, but not much of interest to me until I hit WWV at 15 MC. This is usually not easy to hear in this location and is a sign that the radio is receiving well. I heard a few stations below that between 15 MC and 14 MC. the I heard a number more stations between 12 MC and 11 MC. WWV cam in loud and clear at 10 MC, and there were a lot of stations that came in between 10 and 9 MC. One of the stations I heard on the band was from Bucharest, Romania. Based on this evenings results, I think the SMLR is working fine now. I'll let you know what my revision to the antenna situation does.

[Ken Carr]

Sounds like that Deoxit made a big difference. Keep working at the improvements. You have a great radio that is no longer produced and which few people will ever enjoy. We radio people have all the fun!

[Michael Lawton]

I rebuilt The antenna on the front of my house. I also found that it works better if I do NOT connect the outer braid of the feed in coax to the outside of the plug connector, but parallel it on both ends so that only the actual antenna wire is connected to the center pin. The rebuilt antenna is a good bit taller than the first version, and uses 10 meters of wire total in the upper mast of the antenna and the loading coil at the bottom, which is spaced to reduce inter winding capacitance. It looks like this:

It now works VERY well, and I am able to receive stations from the north including CHU at 3.33 and 7.85 MC clearly as well as Zoomer Radio on 740 KC AM. I use the same antenna for the Hammarlund HQ-180 I bought more recently. What is surprising is how the Scott receives the AM signals I am most interested in, being a shortwave listener and not a Ham, almost as well as the HQ-180, considering the difference in their circuits.

[Ken Carr]

Nice to see you are getting great results! A good antenna makes all the difference in the world. I had my SLRM on top of a military signal generator on the floor of my shop. I could not use it there. Today my neighbor, who is a strong guy, lifted it right up and placed it on a shelf next to my antenna switch. I hooked it up and the reception was amazing! The AM broadcast band and the shortwave bands were bringing in everything. My antenna is a Gap Titan Vertical that takes care of the second floor hamshack and the basement shop.

Michael Lawton said:

I

[Michael Lawton]

Thanks, Ken. I notice you have an HQ-140-XA. I have an HQ-140-X. It was the first Hammarlund I bought, many years ago now, fulfilling a dream I had ever since I was a kid drooling over them in the Allied Radio catalogs I got every year. I haven't fired it up in a few years now. I think I'll make it my next project and at least replace the power supply electrolytics with the replacement from Hayseed Hamfest.

[Ken Carr]

Very nice Hammarlund ! I especially like the brown knobs. That and the change in type of meter seem to be the major external differences between the two.I have not replaced the filter caps on mine (as far as I can remember, anyways). I should follow your lead. If this is like my other Hammarlund receiver (HQ-170), it should have mostly ceramic capacitors which I usually don’t replace. Hopefully yours has mostly ceramics too. These heavy beasts are some of the best receivers ever made. My all time favorite is the SP-600. I have a rack mount version that came off a destroyer.

Michael Lawton said:

Thanks, Ken. I notice you have an HQ-140-XA. I have an HQ-140-X. It was the first Hammarlund I bought, many years ago now, fulfilling a dream I had ever since I was a kid drooling over them in the Allied Radio catalogs I got every year. I haven't fired it up in a few years now. I think I'll make it my next project and at least replace the power supply electrolytics with the replacement from Hayseed Hamfest.

[Michael Lawton]

Yup, Ken, the SP-600 is an amazing receiver for ham work. For my own uses, as a shortwave listener, it would be even greater overkill than the HQ-180 I bought. LOL ! That was another itch I just HAD to scratch, another Hammarlund I swore to my teenage self I would own someday. I own 4 Hammarlunds at this point, an HQ-129-X which I restored and is a daily driver connected to the antenna on my BACK porch, the Hammarlund HQ-140-X, a Hammarlund HQ-145 which I find is really not much better than the HQ-140-X for my purposes, and the HQ-180 which I have written about here: https://antiqueradios.com/forums/viewtopic.php?f=2&t=429433 and here:  https://antiqueradios.com/forums/viewtopic.php?f=5&t=429470&...  and here:  https://antiqueradios.com/forums/viewtopic.php?f=5&t=432141

[Scott Seickel]

Nice looking SP-600 Ken.  They are great band cruisers compared to the R-390 for instance.  SP-600's were all rack mount, but often they can be found in a 19" rack cabinet.  They were actually pretty light weight in comparison to other receivers with their all aluminum construction.  Try picking up an RCA AR-88!!!

[Ken Carr]

• That was a great story, Michael! I picked up on the part about driving from Providence, RI. That is where I was from up until 5 years old. I am now way down south in Hope  Valley, RI. The 180 must be good if it is anything like the 170 (ham only) that I have. The SSB sound on that thing is awesome!
  And I had all the catalogs every year too … the closest I ever came to a shortwave radio was the Hallicrafters S120 I got for Christmas in 1962. My dad probably spent a week’s pay on that one! See me on Christmas day in 1962 using the radio …. no sound… dad took it on an 8mm B&Howell Filmo. (Sorry about the upside down radio. Something happened and I ran out of time trying to fix it.)
• https://youtu.be/MzI8nftVQW0?si=PVjz6KqGaf00tYnJ
  Michael Lawton said:

Yup, Ken, the SP-600 is an amazing receiver for ham work. For my own uses, as a shortwave listener, it would be even greater overkill than the HQ-180 I bought. LOL ! That was another itch I just HAD to scratch, another Hammarlund I swore to my teenage self I would own someday. I own 4 Hammarlunds at this point, an HQ-129-X which I restored and is a daily driver connected to the antenna on my BACK porch, the Hammarlund HQ-140-X, a Hammarlund HQ-145 which I find is really not much better than the HQ-140-X for my purposes, and the HQ-180 which I have written about here: https://antiqueradios.com/forums/viewtopic.php?f=2&t=429433 and here:  https://antiqueradios.com/forums/viewtopic.php?f=5&t=429470&...  and here:  https://antiqueradios.com/forums/viewtopic.php?f=5&t=432141

[Ken Carr]

I think I did try to pick up an RCA once (it had been left outside for a few days in the trash and rain). I gave up on it .. too heavy and too messed up. My buddy carried the 600 up to the second floor of my house. Even that is a bit challenging to me. My limit is the HRO-60. A friend had it on the third floor of his house. He said I could have it if I could carry it down myself. I made it. I was much younger and skinnier then!

Nice to hear from you, Scott. If you are ever in the RI area, I will give you a personal tour of the New England Wireless & Steam Museum. We have more old radios than God. And then there are all the obscure radio parts, literature, etc. We have a great ham shack too. We recently competed in a pre-1930 transmitter contest sponsored by the AWA. We used a 1929 TNT.

Fun stuff!   And yes, we have at least one E.H. Scott, a 1933 model.

Scott Seickel said:

Nice looking SP-600 Ken.  They are great band cruisers compared to the R-390 for instance.  SP-600's were all rack mount, but often they can be found in a 19" rack cabinet.  They were actually pretty light weight in comparison to other receivers with their all aluminum construction.  Try picking up an RCA AR-88!!!

[Michael Lawton]

OMG Ken ! You mentioned the New England Wireless & Steam Museum. I first went there as a kid, maybe 10 or 11 years old. It had been written up in an article in Yankee Magazine. At the time it was just the radio museum, and was run by the old man who owned the farm it is on. He fired up the spark gap transmitter in the room reproducing the radio room of a ship from the early 1900s. I remember how loud it was, and the smell of the ozone it generated in the air. He was a wonderful fellow, and that visit did much to encourage my study of electronics and lit my desire to collect antique radios. I returned several times much later, in the early 2000s and enjoyed seeing how it has expanded. I also learned over the years that the old man I had met had an Indian motorcycle, For over half a century, from the time I was discharged from the Navy in 1972 until I moved from Providence, RI to Sneedville, TN, I owned and rode a 1950 Indian 149 Arrow. Small world, isn't it ?