Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

Atwater Kent 328 Early
#24

Those voltage readings look much more reasonable. The B+ voltage is still a bit high, but this might be a result of todays higher line voltages. The AK schematic specifies a 110V AC line voltage, so you might want to use a bucking transformer or run the set on a variac.

It still appears that one of the 6K7's or the 6A8 is causing the positive grid bias on the AVC line. In normal operation, there should never be a positive voltage on the grid caps. The schematic voltages don't show polarity, but the 5V indicated on the 6K7 grids should be -5V, which would be typical when receiving a station.

You can disconnect one grid cap at a time and see which tube is causing the positive voltage. A gassy tube will produce a positive grid voltage and throw off the bias on all the remaining AVC controlled tubes. The positive grid bias is causing excessive plate current, which results in the higher than normal voltages across R3, R6, R10, R11 and R12.


Messages In This Thread
Atwater Kent 328 Early - by Eric - 09-24-2013, 08:09 PM
RE: Atwater Kent 328 Early - by Radioroslyn - 09-24-2013, 09:22 PM
RE: Atwater Kent 328 Early - by Eric - 09-25-2013, 11:32 AM
RE: Atwater Kent 328 Early - by Mondial - 09-25-2013, 02:51 PM
RE: Atwater Kent 328 Early - by Eric - 09-25-2013, 06:14 PM
RE: Atwater Kent 328 Early - by marty - 09-25-2013, 06:33 PM
RE: Atwater Kent 328 Early - by Eric - 09-25-2013, 07:31 PM
RE: Atwater Kent 328 Early - by Arran - 09-25-2013, 10:35 PM
RE: Atwater Kent 328 Early - by Eric - 09-25-2013, 11:08 PM
RE: Atwater Kent 328 Early - by Mondial - 09-26-2013, 12:05 AM
RE: Atwater Kent 328 Early - by Arran - 09-26-2013, 12:08 AM
RE: Atwater Kent 328 Early - by Eric - 09-26-2013, 03:18 PM
RE: Atwater Kent 328 Early - by Eric - 10-06-2013, 11:29 AM
RE: Atwater Kent 328 Early - by Mondial - 10-06-2013, 11:51 AM
RE: Atwater Kent 328 Early - by Eric - 10-07-2013, 08:54 PM
RE: Atwater Kent 328 Early - by Eric - 10-08-2013, 06:56 PM
RE: Atwater Kent 328 Early - by Mondial - 10-08-2013, 08:28 PM
RE: Atwater Kent 328 Early - by Eric - 10-09-2013, 11:10 AM
RE: Atwater Kent 328 Early - by Eric - 10-09-2013, 05:15 PM
RE: Atwater Kent 328 Early - by Mondial - 10-09-2013, 06:39 PM
RE: Atwater Kent 328 Early - by Eric - 10-10-2013, 03:28 PM
RE: Atwater Kent 328 Early - by Mondial - 10-11-2013, 08:31 AM
RE: Atwater Kent 328 Early - by Eric - 10-11-2013, 08:15 PM
RE: Atwater Kent 328 Early - by Mondial - 10-11-2013, 11:16 PM
RE: Atwater Kent 328 Early - by Eric - 10-12-2013, 11:38 AM
RE: Atwater Kent 328 Early - by Mondial - 10-13-2013, 10:31 AM
RE: Atwater Kent 328 Early - by Eric - 10-13-2013, 12:18 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Studebaker/Philco AC-2687 car radio
Arran, Thanks for checking you manuals. I appreciate that. Let me know what you find. PhilPdouglaski — 08:46 AM
Studebaker/Philco AC-2687 car radio
I have some car radio service manuals, Riders I think (not to be confused with the big blue binders), so I may see if on...Arran — 01:20 AM
Philco model 40-100
Greetings; Here is an update, I found a listing on fleabay for a similar chassis to yours, and it has a photo of what...Arran — 12:58 AM
Philco model 40-100
Greetings; I think I may have found a clue as to what is missing, from a search I made, there is a rear view of the c...Arran — 12:12 AM
Philco model 40-100
I recently acquired a Philco model 40-100 farm (battery) radio. The radio was in very good condition except the red on f...mhamby — 05:59 PM
Studebaker/Philco AC-2687 car radio
Hello, Richard the radio is an AC-2687 Studebaker model. The Philco model is S -5323 and the chassis p/n is S-5523Pdouglaski — 11:52 AM
48-482 rear panel help
The 48-482 is an AC only set as well, featuring a power transformer. While the transformer shouldn’t get “hot”, it is ye...jrblasde — 11:12 AM
Studebaker/Philco AC-2687 car radio
I gave a Chrysler/MoPar car radio from 1954, it was made by Philco, and it uses two chassis, one has the power supply an...Arran — 11:06 AM
48-482 rear panel help
Hello keithchip. You could make a hardboard back for the set, but make sure you provide plenty of ventilation holes in ...GarySP — 11:04 AM
Studebaker/Philco AC-2687 car radio
Welcome to the Phorum, Phil! Lots of friendly help here to assist you along the way! Take care, - GaryGarySP — 10:55 AM

[-]
Who's Online
There are currently 687 online users. [Complete List]
» 3 Member(s) | 684 Guest(s)
AvatarAvatarAvatar

>