R-1051B receiver help

[K2GTM]

Hello all!

I recently acquired an R-1051B HF receiver that needs some TLC.  So far, I've discovered that the power supply board needs new electrolytic caps and some replacement resistors.  (See photos.)  Also, someone had previously replaced four of the rectifier diodes with larger ones and did a messy job of it.  Along with the messy repair, the PCB has some heat damage.  

I could probably get by with just replacing the bad components, but I'd rather see if I can find a replacement PCB that isn't so rough.  Anyone know where I can find one?  

Thanks and 73,
Greg K2GTM

PS - Any additional info on pitfalls/repairs to watch out for would be helpful too!

[WB6NVH]

They all look like that.  At least in my experience.  The original diodes had a higher forward drop and got hot, and most 1051B's were run 24/7 on ships.  You would have to find a really low mileage board to have one that looked any better.

Most of the 1051B's I worked on decades ago would come in with flat tubes in the front end, I guess from running continuously, although the VHF two-way repeaters I had on mountaintops used to run continuously and the tubes stayed fine for years and years.

The frequency standards in these have some oven issues which have been covered over on the 1051 group on QTH.  There are four or five variations of these, with different oven controllers.

The government started crushing all of these up circa 1992, in its infinite wisdom, so they are scarce, as are spare parts.  Fair Radio Sales might have scrap sets with this board but you could very well wind up with one worse than what you have.

I make new lamps out of the old Grimes ones by salvaging the bases and inserting wire lead lamps.  Others have converted to LED's.

There are other issues that would fill a small book -- gummed up motors, chain alignment, loose module socket pins, and on an on. 

The full manual for these is the size of the Los Angeles telephone book. 

[N8ETQ]

     Back in the summer of 98 A joint in CAL.
Was selling these things for $160 ea. I still
have a couple, one works pretty good after
about a 1 week warmup!  IIRC the joint was
called "Murphy's Surplus".

     Not much SW content worth listening to
nowadays, but back when Radio1 was rockin'
the ISB function was cool..


     I agree with WB6NVH, The P.Sup boards
are all cooked out.. Prolly still ok though.
I eventually ended up with 3 of them and on each
one the 15mcy band was DOA.

     Mine are straight R1051/URR's, I think the
"B" variant added 100cy Steps. The document that
applies to the R1051/URR is titled " Technical
Manual for REPAIR OF AN/WRC-1 AND R1051/URR 2N
MODULES". Unclassified 3-mar-1965..


     It goes without saying that unless you have
the extension cables and a slew of support equipment
they are a real PIA to work on at the "Component level".

     It can be done however, much easier with
a few spare modules..  The radio already has a "6 Pack"
in it, I suggest you do the same!


GL

73

/Dan

The term "Six Pack" refers to the Xtal controlled
synthesizer".  Triple conversion, 1st IF 20 or 30 mcy,
second IF 2.85 mcy, final IF 500kc.

[W7TFO]

Murphy's in El Cajon is still there, going strong.

I remember my biggest problem with them was broken bandchange bellcranks (wow, what alliteration!).

Little pot metal devils, they were.

73DG

[K2GTM]

Thanks for the info!

I've been reading the posts on the QTH mailing list - interesting stuff!  Lots of comments on the common issues you mentioned...

I got really lucky and was able to get a newer-version board that looks almost perfect from Fair Radio.  Just need to replace a few of the electrolytics before I wire it in.

I haven't gotten to the point of checking the tubes, freq. synth. or lamps.  I was thinking about going the LED route so I don't have to dig into that area more than once.  Luckily, everything else LOOKS to be in good condition. 

Yes - I've already printed out the manual!  Thank God I can print things like that at work.  Lol...

They all look like that.  At least in my experience.  The original diodes had a higher forward drop and got hot, and most 1051B's were run 24/7 on ships.  You would have to find a really low mileage board to have one that looked any better.

Most of the 1051B's I worked on decades ago would come in with flat tubes in the front end, I guess from running continuously, although the VHF two-way repeaters I had on mountaintops used to run continuously and the tubes stayed fine for years and years.

The frequency standards in these have some oven issues which have been covered over on the 1051 group on QTH.  There are four or five variations of these, with different oven controllers.

The government started crushing all of these up circa 1992, in its infinite wisdom, so they are scarce, as are spare parts.  Fair Radio Sales might have scrap sets with this board but you could very well wind up with one worse than what you have.

I make new lamps out of the old Grimes ones by salvaging the bases and inserting wire lead lamps.  Others have converted to LED's.

There are other issues that would fill a small book -- gummed up motors, chain alignment, loose module socket pins, and on an on. 

The full manual for these is the size of the Los Angeles telephone book. 

[K2GTM]

Hey Dan,

I actually found that Surplus Sales of Nebraska is still selling the R-1051B for $300 each.  They say the translator module is missing, though.

I know!  I wish there was more to listen to.  Just have to leave it on 3880/3885 (which will save my wrist from tuning anyway)!  Lol...

I've heard it's a common issue.  I think it also has something to do with the dropping resistors for the panel lamps...

The six pack idea sounds perfect (no mention of it in the manual, though).   

Thanks for the info!

73,
-G

     Back in the summer of 98 A joint in CAL.
Was selling these things for $160 ea. I still
have a couple, one works pretty good after
about a 1 week warmup!  IIRC the joint was
called "Murphy's Surplus".

     Not much SW content worth listening to
nowadays, but back when Radio1 was rockin'
the ISB function was cool..


     I agree with WB6NVH, The P.Sup boards
are all cooked out.. Prolly still ok though.
I eventually ended up with 3 of them and on each
one the 15mcy band was DOA.

     Mine are straight R1051/URR's, I think the
"B" variant added 100cy Steps. The document that
applies to the R1051/URR is titled " Technical
Manual for REPAIR OF AN/WRC-1 AND R1051/URR 2N
MODULES". Unclassified 3-mar-1965..


     It goes without saying that unless you have
the extension cables and a slew of support equipment
they are a real PIA to work on at the "Component level".

     It can be done however, much easier with
a few spare modules..  The radio already has a "6 Pack"
in it, I suggest you do the same!


GL

73

/Dan

The term "Six Pack" refers to the Xtal controlled
synthesizer".  Triple conversion, 1st IF 20 or 30 mcy,
second IF 2.85 mcy, final IF 500kc.

[K2GTM]

Hey Dan,

Hmm...  I'll definitely keep an eye on them! 

Thanks and 73,
-G

Murphy's in El Cajon is still there, going strong.

I remember my biggest problem with them was broken bandchange bellcranks (wow, what alliteration!).

Little pot metal devils, they were.

73DG