The BC-610-E has landed

[N6YW]

Finally...
The 400lb behemoth lies in state in the back of my wagon awaiting it's journey into the shack to be re-energized
once again. It will be mated with a rather stunning fully restored black beauty, an RCA AR-88. This will be my
vintage high power station, a dream of mine for the last 2 years and now that it's comes to near bearing of fruit,
I ask for some thoughts from any of you that may be of interest in preparation for it's initial power up and checkout.
While it's in remarkably beautiful condition without signs of abuse or neglect, I want to be sure I am approaching this sequence of events properly. The matching BC-614 looks to be in good shape. It seems to have been modified
with an Amphenol 4 pin mic socket and the carbon mic gain control has been taken out of circuit. All of that is minor though, as the priority is powering up the transmitter. What say you Jeeves?
Thanks in advance,
Billy N6YW

[KA0HCP]

I ask for some thoughts from any of you that may be of interest in preparation for it's initial power up and checkout.

"Floor Reinforcement" 

Congratulations on your new radio!  bill

[N6YW]

Thank you 
Here's the receiver. I will post photos of the BC-610 when it emerges from the car.

[N2DTS]

Clean receiver!
400 pounds, I thought the bc610 power transformer I have was that much!

[KA0HCP]

What a gorgeous AR-88.  Just stunning.

All that art deco chrome makes a fellow want to put on a Fedora and double breasted suit with two tone wingtips!

[N6YW]

What a gorgeous AR-88.  Just stunning.

All that art deco chrome makes a fellow want to put on a Fedor and double breasted suit with two tone wingtips!

NO DOUBT!!!!
Hahahahaha! That's a classic response. Perhaps that outfit would suffice for a period photograph for QRZ.

[N6YW]

Here she is...
Bottles are packed in plastic awaiting deployment.
 

[W6DRZ]

Billy,

That's a beauty!  I always preferred the look of the earlier 610s with the segmented front panel as opposed to the later ones with the flat front.  Much sexier!  Matches the 'decor' of the receiver too.  This 610 looks clean, hope it fires right up for you.

Enjoy,
Craig W6DRZ

[N6YW]

Craig
Thank you! As we sip from our wine glass chatting it up on 3870, we can have some fun talking about this extreme love for AM that we have. Watching the "Voice of Victory" segments on youtube really puts this piece of equipment into perspective. While I own a fully restored ART-13 and is one of my prized possessions, this BC-610-E has a certain special appeal and a meaningful statement about our radio history. When we operate such gear, it's presence is a very powerful testament to the time and space in which these transmitters were developed, manufactured and used.
I am grateful to have become the caretaker for this prime example, hopefully for future generations to enjoy, or for as long as that is permissible. If you think about it, we are pretty darn fortunate to be able to have this hobby and have access to these gems.
It has been lightly modified which includes a built in T/R relay with 2 SO-239 connectors. 3B28's were installed instead of 866A's. The grey painted chassis shelves are in excellent condition and not a spec of corrosion is evident. The tube sockets are clean and everything has the look of originality, even the wiring is in good condition. It came with 3 band units and a host of coils from 160 through 20 meters. All I need is the optional snap in vacuum cap for the tank circuit to operate on 160. Does anyone have any recommendations for a good stable VFO?
My Christmas has come early!

[flintstone mop]

These pieces arrived CLEAN??
Great pictures. You'll love the BC-610
Fred

[W3GMS]

Billy,

Congratulations on acquiring the 610!  You will enjoy operating and working on it.  I acquired the same model 610  several years ago from an OT'er that used it exclusively on 40CW.  He never had it on phone!  Unfortunately he is an SK now, but the 610 along with memories of him live on. 

I also had the later "I" version with the flat front.  I donated that to another local ham who did a wonderful restoration on it.  Its up an operational now and that's the best part.
 
Best of luck with it. 

Joe, W3GMS 

[N6YW]

Thank you Joe and the rest.
Today was a fruitful day. I ran all over west Los Angeles looking for a 2 pin 125 volt twist lock connector for the AC mains of the BC-610. Crickets, zilch... NADA! But, all was not lost. I got to work with a non invasive mod.
I fabricated a mounting plate in place of the AC input receptical, that allows a 14/2 with ground pigtail and a Heyco strain relief to take it's place, properly gendered of course. I installed all of the bottles, cleaned contacts and double checked all of the usual stuff. It fired right up! I let it warm up a good 15 minutes and while doing so I set the 80 meter tuning unit up according to the chart, for 3900 khz. I noted good exciter grid drive and proceeded for low power tune up. No carrier but I did get a plate dip of the final. Turned everything off, reseated tubes and cleaned the relay contactors. Viola. 300 watts carrier with a beautiful DC free note on 3945 khz using the crystal I had on hand, into a Heath Cantenna. Going back and forth from Crystal to MO or manual oscillator?, I noticed that the MO mode doesn't have the carrier cleanliness. I viewed all of this with my Flex 5000A just to see the wave form. Ugly for sure, so I will not be using the MO mode. Either a crystal or remote VFO.
At this time, I do not have a microphone wired for the speech amp. Having hyperextended my right elbow yesterday loading a KWS-1 power supply into my wagon set me back for a bit. I am in pain but forging through with this project. My plan is to have this thing lashed up for a Christmas QSO and as of now it looks mighty promising.
I am thrilled to know that it works and that (fingers crossed) something doesn't blow up, suggests that my plan may come to fruition (i love that term) much to my enjoyment.
Here are some photos of today's tests. After my initial trial I am left with the impression that this is a very easy transmitter to use with predictable operating settings and very stable. I monitored the frequency for 10 minutes using the crystal mode and the drift was not noticeable. Granted, I was walking back and forth from the shack to
the back yard where my test lash up took place but it is readily apparent that this one is a good one.
I don't think I could have been any luckier with this purchase. Over the next few days as my arm heals, I will make some cabling interfaces and get a microphone wired up so I can see how the speech amp sounds. I have no idea what condition the mod tranny is in and that will be paramount to my objectives.
I am appreciative in those who have contributed with positive encouragement for this project. This really makes the
effort worthwhile. 
Stay tuned.
73 de Billy N6WY

[N6YW]

And, here's some more...

[N6YW]

And yet, some more...
The handy little Diawa meter is okay for simple tests, but inside the shack everything is all Bird and Coaxial Dynamics stuff, including the dummy load.
More to come.
73 de Billy N6YW

[N6YW]

Does anyone have comments regarding the need for delayed T/R switching to protect the receiver front end?
Also, has anyone rebuilt a band tuning unit to improve operation? I am curious about the tuning unit rehab because of the wave form I saw yesterday when using the manual tuning mode. The carrier was dirty looking. In the crystal mode, the carrier was pristine without any spurs. I am inclined to think the tuning unit could be improved.

Meanwhile, getting ready to rearrange the shack to house the BC-610. With the band conditions the way they are right now, coast to coast ops will be possible. I hope to work some of you guys on 75 meters in the evenings.
 

[KA0HCP]

The master oscillator worked well when new.  Give a thorough going over with attention to component values within tolerance, and especially cleaning all mechanical connections, e.g. bolted electrical connections, and contacts. 

Seventy years of oxidation and aging take their toll, even when it isn't a dramatic failure.

[N8ETQ]

Hey Billy,



    Congratulations on acquiring the 610-E, The last of
the "Pretty Ones". Mine is serial Number 666HX from a
July 1945 contract. Probably why it never left the states.

    Although I have not used it in a couple years now,
I'm sure it will still play.  You will save yourself some
grief by getting those the solid state 866's. Best change
to mine. The 866's would occasionally "Blow Up" for no
obvious reason.

    I use FT-243 rocks on 3885 and 7290 with no problems
and the MO is fine too. The 6V6 osc in the 610 seems
to effect the oscillator a bit. You can try diff. Brands
and it may clean up.

    Put a 2 - 10 Mf cap across the overload relay coil to
keep it from buzzing with modulation. 200V job will do,
if it blows it blows, keep that little box over it.

    No T/R Sequencing required, By the time the plate
voltage comes up with PTT your relay will have thrown.
I use a single Dow Key coaxial job for all my TX's here
and just select the Transmitter in use to control it when
I'm switching the 12 position Coaxial Sw. to that TX.
I see some sparking from time to time at the relay
but that's only when dropping carrier.

    From one of your Pix. It looks to me like your
Modulator Bias is a little low, my 100TH's just show
a little color in the center part of the plate at the
30 Ma. resting level.  The bias rectifier is on the
MOD. deck, You can check it by switching to CW and
if it stays keyed you need to change that.

    The set up here is a pretty much complete
SCR-499 with a home brew JB-70. I too use the BC-614
and I have a BC-312 in the CH-120 Chest also home brew.
The "GI" mic. issued with the set is a T-50 and mine
sounds pretty good.

    Maybe I can get my shack squared around here
and get the Old Beast back on the air. Christmas
sounds like a good time frame.

    Good luck Billy, Please keep the group updated
with your progress.

73

/Dan

[N6YW]

@Dan
Thank you, a wealth of information and I truly appreciate it. The next few days will see a flurry of activity here in preparation of getting it rigged up. There was a rather clumsy attempt at a cap job in the BC-614 that I need to tidy up... nothing worse than soldering new caps onto bad old ones which is exactly what was done and perhaps it was during testing by a previous owner. Clip, they come out and some fresh
lytics take their place. I was not able to get the transmitter to key up in CW, even with a shorted phone
plug inserted into the speech amp. So, some exploration is in store there.

I am going to post a photo of a peculiar temp mod that came with the transmitter. Underneath the tuning unit input circuitry, there is a "hanging" wire wound resistor held in place with clip leads. It appears to be a 20 watt unit and until I move the transmitter into the shack I won't be able to identify what it's doing there. This transmitter came with a lower back panel that's fitted with a blower and a filter box with a removable filter grate held in place with wing nuts. It looks factory and has two holes punched, one on each side to allow access to the ac and speech amp plugs.

More to come, stay tuned!
Thanks again,
Billy N6YW

[N6YW]

@Dan,
I love your shack! It looks like a true basement setup, correct?
The military rigs arranged like that really make it very cool.
 

[N8ETQ]

@Dan,
I love your shack! It looks like a true basement setup, correct?
The military rigs arranged like that really make it very cool.
 

   Thank you Billy, I built my "Entertainment Center" specifically for
the BC-610. The top lifts off to free the 2 side shelves. It's all 3/4"
white Oak ply except for the face trim that's just 3/4" white oak.
My daughter was in a stroller then, she's 24 now...  Your correct,
I'm "Subterranean"

73

/Dan

[N8ETQ]

  I don't recall the details right now but I think you need the
JB-70 to key the rigs oscillator. I think the "KEY" line to the
614 will just put it into TX. There is an additional line to
key the oscillator. I think that comes out of the 614 on the
plug labeled "To JB-70".

/Dan

I was not able to get the transmitter to key up in CW, even with a shorted phone
plug inserted into the speech amp. So, some exploration is in store there.

[N6YW]

  I don't recall the details right now but I think you need the
JB-70 to key the rigs oscillator. I think the "KEY" line to the
614 will just put it into TX. There is an additional line to
key the oscillator. I think that comes out of the 614 on the
plug labeled "To JB-70".

/Dan

I was not able to get the transmitter to key up in CW, even with a shorted phone
plug inserted into the speech amp. So, some exploration is in store there.

Dan, thanks again. The subterranean comment made me bust a gut, funny stuff. I totally get that and to be quite honest, since my childhood, I have always felt that a basement or attic was the "correct" place for the ham shack when a separate out building was out of the question.
If what you say is correct, then it explains why I couldn't get the transmitter to work in CW mode.
I am just getting my spurs with the 610 mind you, so all of this info is quite useful. I have been reading
the manual in small bursts, so absorbing all of the technical aspects is coming a little at a time.
Speaking of shack, I hope to some day build a real period type ham shack from the early 1900's, complete with a pair of wooden towers to support a sky wire fed with open wire feeder. Ah, such is the stuff of childhood dreams but perhaps in my retirement I could chase down that dream. In the meantime, the BC-610 & AR-88 is a gift from the dream catcher if you will, so my steps will be childlike in enjoyment and manlike in signal. I couldn't be happier right now.
Billy N6YW

[N6YW]

Update:
I dug into the BC-614 speech amp today. After familiarizing myself with the schematic, I became discreetly aware of some potential hazards... mainly snipping out some very unsportsman like
modifications, such as "Motor Starter Caps" in the power supply. Seriously, BP caps for the B+.
 
The former whiz who attempted to rewrite electronic history his way further galvanized my opinion
that never take anything for granted, regardless of who or where the item came from.
45 minutes later, the entire power supply filter capacitor circuits were refreshed with current production
500 volt rated lytic's. It should at least breath a little better. I am a little doubtful about the old molded
mica bypass caps though. Opinions on this subject vary but I have a hunch that some will need to
replaced. Aside from the just mentioned repair, the mods done to this unit previous to my ownership were disconnection of the carbon mic circuit, some electrolytic bypassing in the speech amp and a couple of mysterious detours from stock wiring. I should have this figured out in short order.
With the very helpful advice from Dan, I am studying up on the routing of all aspects of the control system via the JB-70 of which I do not have but knowing what goes where and why will fill in the blanks.
I have a rather nice Shure SM57 (old one) and a host of other microphones, including my very favorite high tech state of the art signal processing chain... the D-104. The input cable has been completed.
So, over the next few days, I should have some idea how this beast actually sounds.
More to come, Onward!

[N6YW]

It looks like the mic amp has been modified for a D-104 already.
A view of the inside. The main B+ filter arrangement is in the form of a dual section 50uf @500vdc
can. I left the 2 other old cans in place disconnected and used tubular lytics place mounted.
I will fire it up in the next couple of days to test.

[w3jn]

There was an article in Electric Radio some years ago detailing the problem and fix for the BC-610 master oscillators.  No, they never did work very well even when new, apparently; they had all sorts of FMing and stability problems.