Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

650B RF and Antenna Tuning Characteristics
#1

Hi all,

I have been working on my 650B and have noticed the following characteristics in tuning my radio.


Longwave band.....Antena-Very broad peak.......RF-Sharp peak

Broadcast band.....Antenna- Sharp peak............RF-Very Broad Peak-almost none

Police band............Antenna-Sharp peak.............RF-Sharp peak

Shortwave band....Antenna-Sharp peak.............RF- Sharp peak

I am hoping some of you folks who have a great amount of experience with these 640/650 chassis can weigh in on this. Are the very broad to almost non-existent peaks normal on the broadcast band and the longwave band?

I have noticed that there are two internal capacitors in the rf transformer assembly, caps #16 and #17, associated with the broadcast and police band. I'm not sure of the value of these, but when I measure them with the ohm meter they appear somewhat leaky. Has anyone ever changed these before? What is the value? Could this be the reason for the broad tuning of the rf coil on the broadcast band?

What do you think?

Here is the schematic. http://www.nostalgiaair.org/Resources/824/M0013824.htm

Ed
#2

Ed and I have been discussing this. Really want to hear others opinions.

-Brian
If you collect or are interested in antique telephones, please visit Classic Rotary Phones
http://www.classicrotaryphones.com/forum/index.php
#3

Haven't had time to restore my 650B chassis as yet, so I cannot comment on this. Anyone else?

--
Ron Ramirez
Ferdinand IN
#4

Anyone at all?

-Brian
If you collect or are interested in antique telephones, please visit Classic Rotary Phones
http://www.classicrotaryphones.com/forum/index.php




Users browsing this thread: 3 Guest(s)
[-]
Recent Posts
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
I have a question about this radio, is there anyone that has access to this radio that has an intact unmolested speaker ...captainclock1988 — 04:28 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
Well what makes me confuse all of those companies is that all three of those companies (Setchell-Carlson, Stromberg-Carl...captainclock1988 — 04:21 PM
trying to identify this wire type
The red wire is rubber covered wire. The others are cotton braid over rubber often in colors or a tracer, also strand...Chas — 02:43 PM
trying to identify this wire type
Greetings Phorum members, Hope you can help me identify this type of wire in the photo I have attached.  I am not sure ...georgetownjohn — 01:53 PM
Philco 60 Squealing
All correct shields must be in place, all tubes correct no subs of any kind. Check any soldered, riveted ground conne...Chas — 01:24 PM
Philco 60 Squealing
I have recapped and replaced out of tolerance resistors and so on. Radio plays nicely on fairly strong stations. The pro...dconant — 10:55 AM
Philco 46-420 Code 121 Reception issues
Welcome Eric, I agree with Bob and far as the two main electrolytic filter capacitors did you change them yourself or w...radiorich — 11:43 PM
Philco 46-420 Code 121 Reception issues
You mentioned the Philco manual and going through the check points...just to be sure we're on the same page here's the m...klondike98 — 08:13 PM
Philco 42-1008 conversion kit
Interesting. I haven't seen that before.klondike98 — 07:02 PM
12' Philco
Yes I had looked for it on the web as well some time back and could not find it. I was glad to see it turned up in Ron'...klondike98 — 06:59 PM

[-]
Who's Online
There are currently 4633 online users. [Complete List]
» 3 Member(s) | 4630 Guest(s)
AvatarAvatarAvatar

>