Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

40-150 No Short Wave
#5

It's taken me a long time to finish this, but I finally replaced the converter tube socket and baked the oscillator coil in the oven for an hour with the oven set at 200 degrees F. The thermometer inside the oven tells me it only got to about 160, but I don't know if that's accurate or not.

Once I had the coil out and baked, but before I put it back in the radio, I measured the DC resistance between pins. I should have done that before baking, but it didn't occur to me. Between pins 2 and 3 I got 68 ohms, where the schematic tells me I should have 1.5 ohm. I scratched my head over that for a few minutes and then decided to reflow the solder on the pins to see what happens. After several tries I got the resistance down to about 6 ohms. It wouldn't go any lower. The resistance between the rest of the pins is about nominal, maybe just a little high, so I left them alone.

I put the coil back in, and now I get signals across all three bands. The SW signals are weak, but I just have the loop antenna propped up behind the chassis on my basement workbench, which is not the best place to listen to short wave. Still, now I know the oscillator is working on SW, which it wasn't before.

I'm not sure whether it works because I baked the coil or because I reflowed the solder, but at any rate it's working. Next I'll do a complete alignment and see how things sound after that. I haven't touched the SW alignment since I recapped the radio in 2007, so maybe aligning it will improve things.

John Honeycutt


Messages In This Thread
40-150 No Short Wave - by Raleigh - 11-22-2014, 05:16 PM
RE: 40-150 No Short Wave - by Ron Ramirez - 11-22-2014, 07:20 PM
RE: 40-150 No Short Wave - by Raleigh - 11-23-2014, 12:30 PM
RE: 40-150 No Short Wave - by Ron Ramirez - 11-23-2014, 12:38 PM
RE: 40-150 No Short Wave - by Raleigh - 03-16-2015, 11:07 PM
RE: 40-150 No Short Wave - by Ron Ramirez - 03-17-2015, 06:24 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM

[-]
Who's Online
There are currently 1980 online users. [Complete List]
» 2 Member(s) | 1978 Guest(s)
AvatarAvatar

>