Help with a BC-455-B

[Anthony Bailey]

I've got an old BC-455-B receiver. The problem is I can only hear noise
and that only when the bfo switch is on. I don't get a whine or tones
while tuning with the switch on. The audio level is very low but is
adustable with the volume control from nothing at all to very low.

The one glass tube is lit and the other metal tubes are warm. I don't
have a schematic to check to see if my power supply is outputting the
correct voltage. Any ideas??
Thanks, Tony

[Fifty6K]

>. Any ideas??

Ideas are about it, I had several Command receivers back in the early 50's so
things are foggy. They originally had 24 volt filaments and finding 24 volt
transformers in the 50's was like finding teeth in a hens mouth so most are
probably converted to 6 or 12 volts depending on what the owner had on hand. If
memory serves me right two of the pins on the rear went to a send receive
switch, so you might check to see if you have the B + voltage at the plates, if
not you will need to find these pins and jumper them or install a standby
switch.
I used to have all the conversion manuals but think they have disappeared but
will have a look to see if I can come up with anything.

Rob Mills

[Vank66]

I've got a copy of Command Sets published by CQ magazine,it has schematics and
instructions for all sorts of modifications to the Command sets
BC453,BC454,BC455.
I'll sell it for $5.00 plus postage if you are interested, send me your
address and I'll mail it.

[Vank66]

I've got a book published by CQ magazine which has schematics of the Command
Sets BC453,BC454, BC455 and all sorts of modifications for them.
I'll sell the book for $5.00 plus postage,if interested, send me your
address and I'll get it offf to you.

[Terry Sanford]

..........................................................................................
Try this site.
BC455 etc, circuit diagram at
<www.telalink.net/~badger/milist/sch/cby-46104.gif>

Terry S.

[Edward J. Engelken]

In article <010619991544081074%a63...@semovm.semo.edu>,

Anthony Bailey <a63...@semovm.semo.edu> wrote:
> I've got an old BC-455-B receiver. The problem is I can only hear
noise
> and that only when the bfo switch is on. I don't get a whine or tones
> while tuning with the switch on. The audio level is very low but is
> adustable with the volume control from nothing at all to very low.
>
> The one glass tube is lit and the other metal tubes are warm. I don't
> have a schematic to check to see if my power supply is outputting the
> correct voltage. Any ideas??
> Thanks, Tony
>

The volume will be low if you connect the audio output to an ordinary 4
or 8-ohm speaker. The output impedance of the BC-455 is 600 ohms. You
can use a 12.6-volt filament transformer to match a speaker to your
receiver. Connect the 120-volt primary winding to the receiver and the
12.6-volt winding to a 4 or 8-ohm speaker. Don't apply more than 250
volts B+ to the receiver, that may blow out some of the old capacitors.
A B+ of about 200 volts works well.

Check to see if someone has replaced the output transformer. If so, you
may already have an 8-ohm output.

--
Best Regards,

Ed

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

[cfrank...@yahoo.com]

On Tuesday, June 1, 1999 at 2:00:00 AM UTC-5, Anthony Bailey wrote:
> I've got an old BC-455-B receiver. The problem is I can only hear noise
> and that only when the bfo switch is on. I don't get a whine or tones
> while tuning with the switch on. The audio level is very low but is
> adustable with the volume control from nothing at all to very low.
>
> The one glass tube is lit and the other metal tubes are warm. I don't
> have a schematic to check to see if my power supply is outputting the
> correct voltage. Any ideas??
> Thanks, Tony

look on the internet for info--google the arc-5 or whatever you have--there are tons of info out there,i just ran across a lot-i have an Arct that i converted to 12 volts and 130 for the B plus voltage---n5vog-curtis

[Michael Black]

Well 16.5 years ago, he probably would have had to look in those things
called books, since there was a lot less on the internet.

By now, he either fixed the problem long ago, or tossed the thing.

Michael