Restoring a BC-610: what should I expect? Quality-Wise?

[WX1WX]

Greetings Gang- I'm getting ready to jump into a BC-610-E and restore it. While I've done a few Hallicafters projects before,  like the SX-28 and others, this behemoth is something else altogether. I am well equipped to deal with it and am ready.

My question is this: When its going as well as can be expected… well, what should I expect? I am hearing reports that this venerable warhorse is subject to drift, noise and considerable distortion. Have any of operated this transmitter? How is it, anyway, when in good shape? what issues should I look for? Hoping to hear from you

Thanks in Advance-
de WX1WX

[Todd, KA1KAQ]

Well built, quality-wise. Keep in mind that it's a late 30s civilian design, state-of-the-art then but has the typical issues you mention. I had a E but never got it on the air.

As with other plug-in coil designs, be aware of the B+ and potential and associated hazards involved with reaching inside. Very tempting to do with the flip up door.

Pretty sure a few guys here still run them including Terry W2PFY. They can give you much more detailed info.

[W6TOM]

  Several local guys are working on BC-610 transmitters, all seem to have issues with the VFO, the one I've heard on the air had a noticeable hum. Put in a crystal and it sounds OK. The same guy has used an off board VFO and it sounded OK too.

[WX1WX]

I've seen this and it sound like a reasonable Idea. Finding original rocks is kinda hard to say the least, So a are stable VFO might be a good idea. Any Suggestions?

WX1WX-

[VE3AJM]

Theres some great info on the 610 at http://w1cki.net/


Al VE3AJM

[WQ9E]

There was a note in a fairly recent ER about removing the hum when using the VFO in the exciter units.  I looked at the online index but none of the listed articles rang a bell, I will look through my ER issues later.  I haven't tried to apply it to my BC-610 yet.

[N8ETQ]

    I have used FT243's in mine for since I got it, No problems.
The OC-39 FSK Converter is the Ultimate VFO for the 610 but
a Johnson 122 will work as will his Heath counterpart.

    The MO's probably aren't as bad as you have heard. Before the
"E" model, the SCR-299 was only provisioned for operation up to
8mc. You'll have a big fat carrier filled with audio, so what if some
slopbucket Ahole has to tune every now and then.

     as far as Hum is concerned, run the stock speech amp BC614.
That should mask anything from the TX!  Loose the 866's and find
those solid state jobs for the HV. If your 866 sockets are above
the chassis on 3" standoffs leave it that way, It was a MWO.

     Congrats on the "E", You'll love it.

GL

/Dan

I've seen this and it sound like a reasonable Idea. Finding original rocks is kinda hard to say the least, So a are stable VFO might be a good idea. Any Suggestions?

WX1WX-

[W6TOM]

 I found a Johnson Ranger chassis at a swap less cabinet, a box full of parts, bought it for a friend for $35. When he got a chance to look at it what he found was parts for 2 rangers, the chassis looked to have never been on the air! It was a kit and had numerous mistakes, he got it going and uses the output of the buffer to drive his BC-610, sounds good too!

 He bought two BC-610's from a another guy who lives near San Jose, I helped move the two transmitters the 150 miles to his QTH which is at 3,300 feet in the Sierra Nevada Mountains last Fall.

[N6YW]

Mistake made in my reply.
Sorry.
N6YW

[WX1WX]

Wow-- exciting new folks thanks and keep bringing it on!

Cheers and 73-

WX1WX-

[N6YW]

My 610 will be deployed soon after the shack reconfigure project is complete. CAN"T WAIT!
The BC-610/HT-4 is a dated but very high quality transmitter. Items to watch out for is deterioration of insulation of HV wiring and associated components. I have seen several owners update all of the Anode conductors with Silicone type 10-15KV rated cable. Can't hurt there. Ditch the 866A's and use 3B28's or Solid Stated. Mine uses the 3B28's.
Another item that has been mentioned is the talking relay issue, where the modulation kicks back through the HV center tap and through the coil of RY (5?) causing the thing to chatter with voice peaks. I performed the mod that places a 100 uf 450 volt electrolytic capacitor in parallel with the coil. It didn't make much difference but according to the author it works very well. I will have to dive back into that once I have mine installed... thank God for casters! Speaking of which, I ended up ditching the over built "carriage" frame that placed the casters several inches outside the circumference of the transmitters base... couldn't get the thing through the shop door! I built a new one that makes life much simpler and elegant.
This transmitter is also very dangerous to work on, so be careful. With the rear apron exposed, it is readily apparent that the potential for harm is ALWAYS there, so be careful and use common sense. Do not assume the bleeder system of the HV supply is going to work 100%, so make up a bleeder stick to make sure all voltage is ZERO before resuming any work.
Congrats and good luck!
73 de Billy N6YW

[WX1WX]

Good words! Thank You!

WX1WX

[N6YW]

I wouldn't waste any time with the tuning units. They are "dirty" spectrum wise, while using a crystal is better. I used my Eico 722 VFO and the RF drive was much better and provided near perfect carrier symmetry. The audio path is good, not great but with a little work can be made into a real winner.
When Brian NI6Q runs his 610, it sounds fantastic and does so without a bunch of modifications. I plan to keep mine as stock as practical and I would like to emphasize that it is not intended to be a BC transmitter, so getting the big iron audio like you hear from a Bauer 707 is not going to happen unless some major changes are made. I use the companion BC-614 speech amplifier, and I modified the audio path to more modern specs. The result is very good with great sounding audio using my favorite signal processing... a D-104. I have devised a PTT scheme that will use only a small voltage in the key line.
Also, do yourself a favor, use the very best audio cables you can afford, like Mogami. Cheap cable sucks. It is likely that the multicore cable used from the BC-614 to the transmitter could use a change out as well. Old cable sucks too.
Billy N6YW

[WX1WX]

Intrigued! Good sounding advise! Thanks for the directions!

WX1WX