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

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
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM

[-]
Who's Online
There are currently no members online.

>