1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Threaded Mode
HEATHKIT SG-8 SIGNAL GENERATOR unknown mod?
Bradley Rush
RadioMonkey
***
Posts: 220
Threads: 56
Joined: Oct 2011
City: Lompoc CA
#1

11-29-2016, 12:32 AM
I have a heathkit sg-8 that some one has modified
They put a 8 pin socket on the right upper side.

Pin 5  goes to pin 1 of the 12AU7
Pin 6  goes to RF out jack
Pin 7  goes to ground 
Pin 8  goes to 6.3 Vac 

I ask to find out if any knows of this mod?
 If so what tube should I get?
My guess is this tube is amplifying the RF.
(This post was last modified: 11-29-2016, 10:02 AM by Bradley Rush. Edit Reason: better title )
Find
Bradley Rush
RadioMonkey
***
Posts: 220
Threads: 56
Joined: Oct 2011
City: Lompoc CA
#2
Photo 

11-29-2016, 10:13 AM
This is the front of the SG-8


Attached Files Image(s)
   
Find
Bradley Rush
RadioMonkey
***
Posts: 220
Threads: 56
Joined: Oct 2011
City: Lompoc CA
#3

11-29-2016, 10:17 AM
This is the back


Attached Files Image(s)
   
Find
Radioroslyn
Phorum Expert
*****
Posts: 7,286
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
#4

11-29-2016, 10:52 PM
I doubt it's a socket for an additional tube, probably for some sort of accessory. Maybe an 100kc calibrator.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
(This post was last modified: 11-29-2016, 10:53 PM by Radioroslyn.)
Find
Bradley Rush
RadioMonkey
***
Posts: 220
Threads: 56
Joined: Oct 2011
City: Lompoc CA
#5

11-30-2016, 01:50 AM
With the signal gen  hooked up you could monitor rf plate voltage on the 12AU7 and filaments for stability?
Find
Bradley Rush
RadioMonkey
***
Posts: 220
Threads: 56
Joined: Oct 2011
City: Lompoc CA
#6

11-30-2016, 01:00 PM
HEATHKIT SG-8 now up and going


Attached Files Image(s)
   
Find
« Next Oldest | Next Newest »




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
12' Philco
Wonder if the chassis was big too.daveone23 — 12:38 PM
Philco 38-2 Automatic Tuning
Hi Ron, I have sent Radio Daze my concerns with the dial so I guess we will see. They used my original to make the repro...dconant — 12:27 PM
462ron
Hi Dan, your original dial appears to be lighter, easier to allow light through. My original is similar except it’s crac...462ron — 12:07 PM
Philco 38-2 Automatic Tuning
I received my new 38-2 dial. I'm a little disappointed. As you can see in the picture the blues have a white shadow. The...dconant — 11:13 AM
Philco 38-2 Low Volume
I have been playing my 38-2 for a while now and it is doing very well. I did have to replace the 6A8 (osc) as it develop...dconant — 11:03 AM
Philco Speaker Spider
Hello, Does anyone with a 3 D printer make the spiders for those old Philco speakers? That might be a good idea for some...dconant — 09:41 AM
Philco 16B Parts
Hello, I'm looking to buy a 16B but I'm not so sure of what I am looking at. First as seen from the picture it looks lik...dconant — 09:17 AM
Looking for verification of correct schematic.
Klondike98, Thank you. I'll double check that SN and get back to you. GarySP, Thank you for the schematic.RossH — 12:13 AM
Looking for verification of correct schematic.
I think you have the correct take on your set. Ron's annotated early schematics that note the below B22000 serial numbe...klondike98 — 12:04 AM
Looking for verification of correct schematic.
Hello Ross. The Philco Radio Library located at the bottom of the page has the schematic with the tube count you have. ...GarySP — 10:48 PM

[-]
Who's Online
There are currently 1479 online users. [Complete List]
» 1 Member(s) | 1478 Guest(s)
Avatar

>
  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment