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

Model 90 1st RF question
#1

I noticed that the sensitivity of my 90 was not that great--big, local stations came in okay, but not the regional ones, and at night, only the big blow-torch stations came through, albeit very weakly. I tested my coils, and they all seemed okay, but I was still suspicious of the 1st RF, so I took it out and looked it over:[attachment=1]
Seemed okay, but it looks different than what most people describe as a 1st RF coil: the primary is inside the tube on its own spool. Here's what it looks like underneath: [attachment=0]

If I bypass this coil and hook the antenna directly to the 2nd RF, reception is much, much better, more sensitive and more clear. So there has to be something wrong with the 1st RF, right? But they all test continuous on my ohmmeter, and none of the coils shows more than 6.6 ohms resistance.

Question: how would I go about rewinding the primary on this coil? How do you get the center spool out of the form? Is this even the correct RF coil for this radio? Could someone have substituted it from something different? If the coil is okay, what could be causing the weak reception through it?

Lots of questions. Hope someone has some insight!

Mike


Messages In This Thread
Model 90 1st RF question - by mgutierres - 03-18-2011, 12:26 PM
RE: Model 90 1st RF question - by brett2752 - 01-28-2024, 04:27 PM
RE: Model 90 1st RF question - by Chas - 01-28-2024, 06:51 PM
Re: Model 90 1st RF question - by Ron Ramirez - 03-18-2011, 01:36 PM
Re: Model 90 1st RF question - by 7estatdef - 03-18-2011, 06:18 PM
Re: Model 90 1st RF question - by Steve Davis - 03-19-2011, 07:08 PM
Re: Model 90 1st RF question - by mgutierres - 03-23-2011, 10:01 PM
Re: Model 90 1st RF question - by 7estatdef - 03-24-2011, 02:10 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
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
The list of my radio & TV collection!
Magical chords of forgotten melodies, old nostalgic music on an old radio... Saturday night blues on the Mid-Waves on an...RadioSvit — 12:20 PM
Philco 42-345 Restoration/Repair
Thank you MrFixr55 the issue with this radio is that the internal coil antenna is missing and there was a wire in its pl...osanders0311 — 11:34 AM
Philco 610B oscillator wiring
Regarding the oscillator circuit which is comprised of the 6A7's cathode, control grid, and screen grid. These elements ...Radioroslyn — 10:33 AM
Philco 42-345 Restoration/Repair
Hi OSanders, First off, welcome to the Philco Phorum where Phine Phamily-Phriendly Pholks Phull of Philco Phacts and P...MrFixr55 — 08:41 AM
Philco 42-345 Restoration/Repair
Today I've been reading through the site trying to learn more about this radio. I also soldered the lose power cord cabl...osanders0311 — 08:24 PM
Philco 610B oscillator wiring
Thanks David! I do have that same later prodution model 610 schematic. I've also studied the Philco service bulletins fo...Tubester — 08:12 PM
Philco 610B oscillator wiring
Some info from Beitmans says late production. David   David — 06:06 PM
Restoring Philco 96
Oh wow! Just found this thread.  Brings me back to early days on this phorum.  I did a 96 back in 2017.  Thread here: ...rfeenstra — 06:05 PM
Philco 610B oscillator wiring
Thanks for the replies. It's not the really the hum that I am after. Just trying to understand why only the shortwave ba...Tubester — 04:01 PM

[-]
Who's Online
There are currently 1920 online users. [Complete List]
» 4 Member(s) | 1916 Guest(s)
AvatarAvatarAvatarAvatar

>