Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Aug Tue 20, 2019 5:16 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 4 posts ] 
Author Message
 Post subject: Channel Master 6519, 6523 and Sanyo 10S-10PN S-meter
PostPosted: Sep Wed 04, 2013 4:42 pm 
Member
User avatar

Joined: Feb Thu 24, 2011 3:13 pm
Posts: 913
Location: Ironwood, MI
Been working on a Channel Master 6523 3-band "Trans World" portable. It's the same as the CM 6519 and Sanyo (who makes it for CM) model 10S-10PN. All three have a "signal level meter" that is tied to the IF coil coming off the 1st IF transistor's emitter. It seems that I recall that when no signal was being received this meter was also supposed to function as a relative batteryvoltage indicator. Can anyone refresh my memory if this meter is indeed used for this two-fold purpose? Thank you.


Top
 Profile  
 
 Post subject: Re: Channel Master 6519, 6523 and Sanyo 10S-10PN S-meter
PostPosted: Sep Wed 04, 2013 9:36 pm 
Member
User avatar

Joined: Jun Tue 21, 2011 8:27 pm
Posts: 3288
Location: Flint Hill, Virginia
~ Mitch ~


Last edited by PBPP on Jan Tue 10, 2017 5:53 am, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: Channel Master 6519, 6523 and Sanyo 10S-10PN S-meter
PostPosted: Sep Wed 04, 2013 10:44 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 20475
Location: Utica, NY 13502 (USA)
Actually, the signal level meter is connected as an ammeter measuring the collector current of the 1st IF transistor. When AVC is applied to the 1st IF transistor, less current is drawn so the meter reading is less. With no signal, the meter is at it's maximum (but not necessarily full scale). As the battery supply voltage drops, the maximum reading on the meter will be less which would give a rough indication of battery condition. There is an AVC adjustment whose setting is described at the beginning of the alignment procedure. I have to assume that this affects the meter reading also.

Dave


Top
 Profile  
 
 Post subject: Re: Channel Master 6519, 6523 and Sanyo 10S-10PN S-meter
PostPosted: Sep Thu 05, 2013 1:28 pm 
Member
User avatar

Joined: Feb Thu 24, 2011 3:13 pm
Posts: 913
Location: Ironwood, MI
Thank you Mitch and thank you Dave. You have provided me with some very helpful
information.

Mitch, thank you for the Sams et cetera et cetera; all those things I covered in my PM.

Dave, I so appreciate your explanation of that meter. I stared at the schematic and scratched my head and the only conclusions I could come to were:

A) I had a faulty memory and the tuning meter in fact did not give you a relative indication of the battery voltage, or

B) It measured relative signal off the IF that varied with AGC when there was a signal and, when not provided a relative indication of the 1st IF emitter. You confirmed that. I lost the little meter face card that went inside the tuning meter however just got a good picture of one which I am going to try to fabricate. Indeed it has a "battery" range where ostensibly the meter's needle will rest when the emitter voltage (fed by the battery supply) is in its normal range.

Thanks to you both for so much help!


Top
 Profile  
 
Post New Topic Post Reply  [ 4 posts ]  Moderator: Dave Doughty

All times are UTC [ DST ]


Who is online

Users browsing this forum: xrhonda91 and 4 guests



Search for:
Jump to:  




























Privacy Policy :: Powered by phpBB