Geezer Radio Alert: RME 69

[N6YW]

Another BA from the 30's is coming back to life, a rather forlorn RME 69 that has been neglected for
what must have been several decades. Every single molded paper and electrolytic cap is being replaced
and for the time being I am nearly done. Not ready to tackle the molded mica's yet, and I will need some
help with suggestions on what to replace them with.

It came to life around 7:00 PST this evening.
It's a timeless thrill to witness an old scrappy dead thing come back to life, and while it will need some
considerable work to make it as right as it can be, I believe it's worth it even if it's performance isn't
what I am accustomed to. There is something special about the pre war equipment that holds a certain
reverence from my own personal historical perspective.

I heard WWV on 5 & 10 megacycles and what blew my mind was that the dial position was pretty darn
close to being accurate. The bandspread tuning dial of the 69 is a little different than say the Hammarlund's of that era. From what I gather, the dial is set to mid scale to zero the main tuning
scale position. I am digesting only the first reading of the service manual and in all truth, servicing receivers is not my strong point. Having this one is going to be a good exercise in learning how to
align and peak it for maximum performance, within it's limitations.

I will be reconing the speaker as it's shot to hell. For the time being, I am going to temp install a standard single ended output transformer with a 4 ohm output so I can monitor in a more standard fashion. I will also repaint the cabinet and faceplate with Geezer Wrinkle paint, my personal fave.
I have the feeling that the S meter movement is bad, so I will need some help figuring out a solution
for that. Advice and opinions very much appreciated.
Pictures will be posted tomorrow.
73 de Billy N6YW

[WQ9E]

Billy,

If you didn't find the line bypass caps carefully check under the cover on the bottom of the power transformer.  A number of RME receiver models hide them there and when they short they will burn the bottom of the transformer.

The RME-69 is still very usable today.  I live about 25 miles from the original RME factory site so I have picked up a lot of RME receivers over the years.  My favorite is a RME-70 with the built in preselector resulting in a very wide receiver and I also have a RME-9D, RME-69, RME-99, RME-45, RME-4300, RME-4350, and RME-6900.  I also have something that apparently was a prototype that came in between the RME-70 and 99. 

Enjoy your RME-69!

[Todd, KA1KAQ]

Keep your eyes peeled online, Billy. Those Rola speakers show up from time to time, sometimes without the cabinet. I'm still looking for a DB-20 & speaker for might, though not actively. All good things in time. Had my first -69 back in the early 80s but sold it at a yard sale, it was pretty scruffy. Picked up a nice one from the collection of Chuck/K1KW a couple years back.

They do work fairly well if you keep in mind that they're a 1930s design. The preselector makes a noticeable difference. The Hammarlund Super Pro and HRO were better sets, but also cost considerably more in the day.

One thing they got right was the dial material. Doesn't darken like the Hallicrafters, RCA, and other celluloid dials of the day. Every RME-69 dial I've seen looked like new.

[w8khk]

Billy, thanks for sharing your experience with your RME 69.  I picked up a 69 at Dayton in 2006, it is missing the cabinet and has a substitute meter without the S-meter scale.  Be careful when working around the meter terminals, they have high voltage on them and it bites, ask me how I know.  

My dad bought a 69 new in 1939, my grandfather used it for many years, and now it is in my collection.  The only problem is the bandswitch needs attention so that all bands will work reliably.  

The chassis is cast aluminum, which really adds to the stability, and with proper alignment, the dial is surprisingly accurate.  I am very impressed with how smoothly the dials work on both receivers.  Painting the cabinet and panel should be no problem, because RME did not put any legends on any of the controls. We re-painted my dad's HRO-50 a few years ago, and after a single black spray the crackle texture of the original pain on the cabinet and panel was preserved, it looked brand new when re-assembled.

Perhaps you could share some photos of your progress and the completion.  It is a fun receiver, I am sure you will enjoy using it.

I also have a 4300 in my collection, but have not yet started restoration on that one.

[N6YW]

Thanks for the replies.
I have the trapezoidal speaker, complete. The effects of time and various storage locations rendered the speaker cone into dust and flakes. I have the best speaker recone specialist in the USA just around the corner and he has a vast inventory of hard to find parts. I'll have to go pull it out to verify but I believe the speaker is the large horse shoe magnet Rola Alnico speaker.
My set here seems to be a variant from the photos I have found online. It's finished in battleship gray Geezer wrinkle paint, both units. Most I have seen are black. When I came into this piece, it had suffered
a hit where the tuning window glass was broken, apparently from a fall. The S meter needle does not move freely either, so I suspect it may be a goner, not sure yet.
It was also in a state of being disassembled, but fortunately all of the parts were in a box.
So the questions are many but I have a feeling that shooting the metalwork with Black wrinkle paint and a gray over spray would render it back to form. Or, should I just go with the black? What do you think?
By the way, if anyone is looking for a good geezer wrinkly paint, your local auto parts store will likely carry the High Temp version produced by VHT. I have used it for several projects with outstanding results. Check it out here: http://www.vhtpaint.com/products/wrinkleplus/
After I finish delivering a KWS-1 to Wayne Spring today, I'll be back at the bench gettin after it.
This is turning out to be a fun project. I will keep you posted on the ongoing story.
FUN!

[WQ9E]

Meters are often easily repairable IF the coil is still intact.  First make sure the glass didn't get pushed back a little ways which will freeze the pointer.  If the glass is loose it should be cemented back in place (or clamped depending upon the style/construction).  If this isn't the problem use a good quality magnifying device to check for any stray material between the moving coil and the pole piece, remove if present.  Make sure there are no "whiskers" from the meter scale contacting the pointer.  If none of these are the cause then it is time to carefully loosen and reset the front and rear bearings since things can shift when mechanically shocked and I have seen meters where the moving assembly was knocked out of the bearing points.  You want the coil to be properly centered and generally the flatness of the two "clock springs" are a good indicant of this but it sounds like your receiver may have received a strong hit and this can bend these supports.  So if when the springs are perfectly flat if the coil doesn't appear to be centered (front to back) in the pole piece you will need to slightly adjust the bearings to center it and VERY carefully bend the spring mount points so they are flat.  If the springs are not flat then the meter movement will catch. Proper bearing tension can be easily set by increasing to the point where there is a minute drag and then backing off about 1/4 turn.  Too tight doesn't work but too loose will also cause problems.

Good luck!

[N6YW]

Meters are often easily repairable IF the coil is still intact.  First make sure the glass didn't get pushed back a little ways which will freeze the pointer.  If the glass is loose it should be cemented back in place (or clamped depending upon the style/construction).  If this isn't the problem use a good quality magnifying device to check for any stray material between the moving coil and the pole piece, remove if present.  Make sure there are no "whiskers" from the meter scale contacting the pointer.  If none of these are the cause then it is time to carefully loosen and reset the front and rear bearings since things can shift when mechanically shocked and I have seen meters where the moving assembly was knocked out of the bearing points.  You want the coil to be properly centered and generally the flatness of the two "clock springs" are a good indicant of this but it sounds like your receiver may have received a strong hit and this can bend these supports.  So if when the springs are perfectly flat if the coil doesn't appear to be centered (front to back) in the pole piece you will need to slightly adjust the bearings to center it and VERY carefully bend the spring mount points so they are flat.  If the springs are not flat then the meter movement will catch. Proper bearing tension can be easily set by increasing to the point where there is a minute drag and then backing off about 1/4 turn.  Too tight doesn't work but too loose will also cause problems.

Good luck!

Roger
Thanks for the hints. I suspect that it's as you suggested about tensioning. The coil looks to be intact.
I have good magnifying equipment and steady hands. I will remove it from the front panel this evening to see if I can free it up. What I find interesting is the presence of over 200 volts on the meter leads. As mentioned earlier, is this normal? This suggests (in my pea brain) that the circuit is a direct current
meter arrangement, no?
I'm off to see the wizard... of Orange County.

[W3GMS]

My set here seems to be a variant from the photos I have found online. It's finished in battleship gray Geezer wrinkle paint, both units. Most I have seen are black.

Billy,
I have two RME-69's and one is black and the other is the gray color you mentioned.  I always thought that the gray units were Navy units but I am really not sure.  I also have the matching gray wedge style speaker enclosure to match it.  I don't know of what electrical differences if any between the black and the gray models.  I will have to see what manuals I have in the file cabinet for them.  I also have an RME LF-90 which is the low frequency converter.  Its black so it matches the black 69 I have.   

I really like all of the RME receivers I have.  I had a 4350A many years ago and it was a very good performer.  I let it go but have since picked up another one.  The vernier drives can be a bit tricky in the 4300 and 4300.  Many times it just the grease that gets old and dried up.  Sometimes the bearings gets flat spots on them but I found a new source for the ball bearings.  I have a 4300 and also some of the VHF converters RME manufactured. 

Bill, W2DGB has become somewhat of an expert on figuring out how to rebuild the vernier assemblies.  He has several and went thought the entire learning process a few years ago.  If everything is right, they do work very well.  Many folks forget about excessive drag from parts downstream such as the tuning condenser.  If they are gummed up they will mess up the loading on the vernier and it will have problems. 

Have fun with your project!

73,
Joe, W3GMS     

[N6YW]

Joe
Thank you for the reply. I just walked away from a session with my initial tune up and I must admit,
I need to reread and rethink the approach. From what I have found so far, is there were at least 3 variants
of the 69 which in addition to your LF version, there was also one with provision for battery use and likely used a vibrator unit.
Anyway, tonight is alignment and if I have time, S meter troubleshooting night. The way that RME did things is different from other receivers of that era. I am learning a lot and hopefully my pea brain can absorb what the secret is to succeeding in getting this thing to play. I might need a shrink and a belt of Bourbon to keep me right. Wish me luck. 
Billy N6YW

[N6YW]

Well, listening to the Lakers get blown out by the Thunder was heard on the 69 tonight, which means I was somewhat successful in getting it working. More to the story is the S meter problem was solved by using two meters to make one good one. The 69 meter was badly damaged internally with the rear spindle spring being broken and the geometry of the metal support tabs being out of alignment, I decided to ward off any notion that I am a watch repairman on a Friday night with a cold beer next to me.
Instead, I took the case and glass/bezel and combined it with a meter from my old SP-600 that had a broken glass face. The two fit together well. I was not able to use the face of the 69 meter unfortunately. The face screw holes do not line up. What do ya know, the meter works FB. I love it when improvisation works on the fly... something I have become rather good at over the years... out of necessity. You may recall that I use the term "pea brain" quite often when describing my gray matter. Nuff said.
The alignment process is easier after I was able to get in the ballpark, and that in of itself was the biggest hurdle. Once I had the IF more or less set, the RF alignment commenced. This is where the balancing act is starting to take shape. You have to sacrifice a little sensitivity to gain frequency accuracy and the extra gift by design is the image problem and I am starting to understand what many have said about this.. The design scheme without the DB-20 preselector certainly underlines the deficiencies of this receiver but it makes up for it with coolness factor. My biggest gripe in getting it to align is that confounded bandspread tuning. The manual keeps referring to using it in conjunction with the crystal phasing control in order to resonate the front end so you can peak the alignment. I'm not sure, but there must be a better way. Tomorrow is another day. I need to spend more time in getting the thing to play better, so the next step for me is to test all of the tubes and try to find the source of some of the distortion I am hearing. It's either a tube or two, or resistors & molded mica caps that have
fallen out of spec. All of the other capacitors are new.

So far, I have a piece of gear about 75 years old that was dead and given up on, and now 2 days in, it  has a heartbeat, making sound and producing some childlike fun at my expense... exactly how I like it.
I couldn't be happier at the moment. I took a shot of it on my bench after I finished modifying the meter. With the heat wave expected over the weekend, perhaps some painting is in order.
Thanks for reading and sharing. This is a very fun and educational project.
73 de Billy N6YW

[WQ9E]

Billy,

It sounds like you are making good progress.

A couple of notes on the alignment and I assume you are working from the service manual for the RME-69 printed by RME.

Much of the manual assumes you either don't have a signal generator or a poor signal generator.  Aligning the IF can be done much like any other receiver with a crystal filter.  With your signal generator Inject (through a DC blocking capacitor) into the mixer and find the actual peak frequency of the crystal.  Then align the IF to that frequency.

Make sure to use the correct instructions if you have the LS-1 installed in your receiver.

With the RME calibration on the higher bands is definitely a compromise-especially after years of the coils aging.  Make sure that the band spread cap is properly positioned and that the rotor plates are centered with the stator plates for both capacitors, adjust if necessary before beginning alignment.  The best compromise for the higher bands where there is only one cal adjustment per band is to pick a frequency somewhere around 75% of the maximum frequency of that range and adjust there, from experience that is a pretty good compromise setting on receivers that don't have adjustments for the low and high end.  It is VERY easy to track on the wrong side on the higher bands with the RME-69 so I strongly suggest using an external receiver for the HFO adjustment, you should hear the HFO at roughly 465 Khz. higher than the dial frequency.  465 Khz. lower is tracking on the wrong side.

When making the Ca and Cb adjustments there will be oscillator pulling so use a broadband noise source (a CFL will do) for these adjustments.

Attached are photos of your receiver's older and younger brothers  The "mystery RME" appears to have been a test model that led to the RME-99.

I have original RME-69 and DB-20 brochures along with the 1938 factory price list I picked up last year at a hamfest.  I can scan and email copies of them if you wish later this weekend.