RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Boatanchors (https://www.radiobanter.com/boatanchors/)
-   -   BC-348 receiver help. (https://www.radiobanter.com/boatanchors/5330-bc-348-receiver-help.html)

Uncle Peter January 27th 04 11:00 PM


"Rob Mills" wrote in message
news:eTxRb.470$Le3.182@okepread04...

"HeavyMetal" wrote in message
...

By the way, the tube is a four pin..


The conversion manual (1948) that I have shows a 5Y3. RM~

A 5Y3 is the modern electrical equivalent to an x80 tube, and
much cheaper. Change to an octal socket.

Pete



N2EY January 27th 04 11:55 PM

In article ,
r (Mike Knudsen) writes:

The B- must be fed thru a filter choke, whose toehr end delivers it to
ground. The negative back bias developed across the choke is used to bias
the
audio output tube's grid negative. Its cathode is straight grounded, so if
you
run without this choke and B-, the output will draw excessive current and
distort.

That choke is in the same sealed case as the output transformer.


Exactly. The wires that come to the dynamotor include "B-" which is not
grounded. Hook it up as described and the choke will be in circuit.

A question for the poster I'm responding to: Is that 220 VDC max including
the choke, or just from B+ to chassis ground? I'm assuming the whole thing
(choke included).


It's what you see from B+ to B- at the output of the supply. There's a whole
description in the manual. The idea was to compensate for dynamotor output
variations.

73 de Jim, N2EY




Brian Goldsmith January 28th 04 08:22 AM


" Uncle Peter" wrote

A 5Y3 is the modern electrical equivalent to an x80 tube, and
much cheaper. Change to an octal socket.


***** Modern? Seventy years ago more like!!!!!!!!!!

Brian Goldsmith.




Lynn Coffelt January 29th 04 06:38 AM


"HeavyMetal" wrote in message
...
Thanks to all for the comments and suggestions.
It's a great ol' receiver. I really like it.
I'll keep everyone posted on the progress.....


Most often, what appears to be a shorted rectifier tube... It glows and the
plates turn red.... is not the tube itself, but a shorted capacitor
somewhere in the B+ wiring. There will be no charge for this diagnosis.
Old Chief Lynn W7LTQ since 1948 (first real receiver BC-348Q)



-Bill- January 29th 04 07:47 AM

Lynn Coffelt wrote:
"HeavyMetal" wrote in message
...

Thanks to all for the comments and suggestions.
It's a great ol' receiver. I really like it.
I'll keep everyone posted on the progress.....



Most often, what appears to be a shorted rectifier tube... It glows and the
plates turn red.... is not the tube itself, but a shorted capacitor
somewhere in the B+ wiring. There will be no charge for this diagnosis.
Old Chief Lynn W7LTQ since 1948 (first real receiver BC-348Q)




RADIO 101....question all paper or electrolytic caps in a sixty year old
radio. "works fine, but..." is always the wrong answer.

-BM


Josh January 31st 04 12:22 AM

The electrolytics was changed out as well as some paper caps.
One of the wires in the tube is broken and banging about..I think it shorted
and the trouble. Will keep posted..Thanks..Josh
"-Bill-" exray@coquidotnet wrote in message
...
Lynn Coffelt wrote:
"HeavyMetal" wrote in message
...

Thanks to all for the comments and suggestions.
It's a great ol' receiver. I really like it.
I'll keep everyone posted on the progress.....



Most often, what appears to be a shorted rectifier tube... It glows and

the
plates turn red.... is not the tube itself, but a shorted capacitor
somewhere in the B+ wiring. There will be no charge for this diagnosis.
Old Chief Lynn W7LTQ since 1948 (first real receiver BC-348Q)




RADIO 101....question all paper or electrolytic caps in a sixty year old
radio. "works fine, but..." is always the wrong answer.

-BM




Jan-Martin Noeding, LA8AK February 22nd 04 10:21 AM

On Tue, 27 Jan 2004 18:00:13 -0500, " Uncle Peter"
wrote:


"Rob Mills" wrote in message
news:eTxRb.470$Le3.182@okepread04...

"HeavyMetal" wrote in message
...

By the way, the tube is a four pin..


The conversion manual (1948) that I have shows a 5Y3. RM~

A 5Y3 is the modern electrical equivalent to an x80 tube, and
much cheaper. Change to an octal socket.

Pete

By the way, isn't 5Y3GT a 5-pin octal tube?

JM
----
Jan-Martin, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/


All times are GMT +1. The time now is 09:52 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com