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

The innards of that AK 20 Big Box set
#19

(06-29-2015, 08:18 PM)Radioroslyn Wrote:  Well the voltage look good so I think you have something that is open. So let measure the resistance from the 1st tuning cap stator to the rotor. Then measure the resistance from the stator to the grid pin of the first rf tube. Measure the resistance from the ant post to the stator. Rotate the ant switch. All should show a low resistance.

Terry

You are on to something here! 1st tuning cap star to rotor=4.7 ohms, Stator to grid pin=689 Kohms!!!, antenna post to stator=16 ohms? But when I turned the antenna switch to the different contacts, the ohmage dropped to 2 ohms or so.

689K! I'm measuring the grid resistors, of course. In my defense, I am profoundly colorblind, so color coding is lost on me. I have to rely on position of the light at stop lights, and I simply misread 689K as 689 Ohms. Stupid.

I have to go to the local electronics store for the correct homage resistors, but I should have it soldered in by this evening. I guess your advice and a good night's rest is all I needed. I feel dumb, but excited. Thanks.

I have the new resistors in on both tuning caps, and the radio sounds clear and strong through my headphones. I'm wondering if the signal isn't strong enough to drive my AK model E speaker? At any rate, thanks for all the advice.

Charlie in San Antonio


Messages In This Thread
RE: The innards of that AK 20 Big Box set - by ccomer1955 - 06-30-2015, 12:53 PM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
HiFi (Chifi) tube amp build - but my own design.
What may be lacking in the PP Tube amps may be the 2nd harmonics, which some, especially RCA back in the day called &quo...MrFixr55 — 05:32 PM
Jackson 715 not working
Usually in an emission tester, the tube under test is measured as if it were a diode. So, some testers connect all the g...RodB — 04:17 PM
Restoring Philco 37-604C
Yep. F5 is green, D5 is Red. Red is Bad. Green is Clean.morzh — 01:30 PM
Jackson 715 not working
I did start to do that but I stalled out because I could not figure out how the grid and plate get voltage. In this diag...daveone23 — 11:52 AM
Restoring Philco 37-604C
(Insert Homer Simpson "DOPF" Here.) When all fails, look at the can. Took the Ron Ramirez advice, red Caig D...MrFixr55 — 09:23 AM
Philco 91 Speaker Replacement
From your text I am not sure if you intend to use the existing speaker with a resistor instead of the field coil. It wo...morzh — 08:44 AM
Philco 91 Speaker Replacement
My field coil is bad. I am still hoping to find an original, but if I can't I will go with a fitting Philco speaker, 125...dconant — 08:34 AM
Philco 91 Speaker Replacement
As Rod said, it is OK to use a fitting speaker, and then look for an original one. If you buy a Hammond 125 output tr...morzh — 08:15 AM
Philco 91 Speaker Replacement
Yes, I often have to substitute, then keep an eye out for an original. In the meantime, the radio is working and being e...RodB — 08:02 AM
Philco 91 Speaker Replacement
I was wondering if I could use a more common Philco speaker and just add the resistance I need for the coil and get a ne...dconant — 07:45 AM

[-]
Who's Online
There are currently 2438 online users. [Complete List]
» 2 Member(s) | 2436 Guest(s)
AvatarAvatar

>