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

new guy again,, 44 chassis
#16

Bob - I don't see Model 44 instructions among our downloadable files. Is that your scan?
#17

Nathan, check your email.
#18

Done. Icon_thumbup
#19

I am still going on with this, I did get one spanish station (not real clear)
3 questions
1. anyone know what band is FM? (the dial knob has 4 spots just wondering which on is FM)
2. I am gonna start checking the coils in more detail do you guys just ohm them?
3. Is there some type of RF signal generator you use to insert a rf signal for troubleshooting?

thanks all this piece is beating me up
#20

The 44 does not have FM. FM as we know it today did not start until post WWII. There was some FM in the early 1940s but on a different frequency range than today's stations. Your set has 4 bands. Three shortwave bands (that range from 1.5 to 23 megahertz and one broadcast (known today as AM) band. The schematic info has the ranges for each of the bands. The AM band is selected by turning the wave-band switch fully counter clockwise. (see the instructions)

Yes you can check the coils by just checking their resistance. Usually something in the range of 10 to 30 ohms. The schematic has the values on it.

Alignment is done with a signal generator that supplies an RF signal with an audio frequency modulating it (usually about 400 Hz). An example (I'm not suggesting you buy this one) that is currently on ebay is seen at this LINK.
#21

As a slight addendum to the FM discussion, the 1942 Philco 42-400 that I restored a few years ago had the old-style FM circuit. I was able to attune the circuit to receive the full range of the modern frequencies, apparently compressing the signal to fit into the spectrum, then spreading it over the bandwidth, so it actually tracked quite nicely up and down the scale and received all the stations as far as I could tell- as many as my modern FM test radio I had there. The FM scale wasn't so precisely marked upon the dialface, so it was close enough, and the FM sounded marvelous! I think Ron attributed that PHenomenon to some kind of oblique harmonic resonance signal that it was picking up. However the method, it worked! I guess when you spend about 100 hours or so aligning it up by ear, you're bound to stumble upon a big surprise. Or was it just lady luck there smiling? It was almost surreal hearing grunge rock blasting out of that beautiful console!   Icon_cool
#22

Sorry guys I meant which position is AM not FM
#23

Ok I replaced all of the caps and the resistors still had the same, then I adjusted the 1ST AND 2ND I.F coil adjustments and I got AM 1060 (our local strong station to come in )

My question is this piece has
3 adjustments on the back (wave trap and 2 compensating condensers)
2 I.F coil adjustments (on top of the coils)
2 Osc. adjustments (on top of the tuner)
Anyone have any thoughts on these adjustments? and how if at all to adjust them without a boat load of equipment?
thanks all !!
#24

Mike, he mentioned that he meant AM instead of FM a couple posts back. He was also asking about a signal generator so I think the answer is "no" to full alignment.
#25

Ok then. The questions are withdrawn. Still needs the alignment.
If there's no generator there's no good sub for it. But if it is anywhere near the required frequencies (read - receives some stations in the general vicinity of where it should be) and a strong local station is present, it could be used as a sub.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#26

Thought id start a new thresd [the new thread was merged with the original thread to keep the discussion together..Moderator]
question I have is Does anyone know or can explain the 3 Adjustments on the back?

3 adjustments on the back (wave trap and 2 compensating condensers)  
I would think they would be for the end user to adjust(do to there location)
#27

29 and 30 are 1st IF alignment.
3 is IF trap and can be disregarded.
in fact it all is shown on page 2 in Figure 2, which also has all other alignments explained.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#28

I merged your new thread with the original 44 chassis thread to keep the discussion together per the Phorum Rules.  

As morzh notes, those adjustments on the back are used to align the set and are described in the schematic information found on nostalgiaair.  They were not meant for the home user to adjust since they require some knowledge about the alignment procedure.  I have never done an alignment on a 44 but generally it is done with a signal generator mentioned in an earlier post with adjustments to the various IF transformers and the oscillator in a particular order with the correct signal generator settings while monitoring the output voltage across the output transformer primary.

Here's a summary alignment chart taken from John Riders "Aligning Philco Receivers" from 1937, p. 66.

[Image: https://www.dropbox.com/s/wr9z55mx92s7k1....jpg?raw=1]




Users browsing this thread:
[-]
Recent Posts
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
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

[-]
Who's Online
There are currently 2611 online users. [Complete List]
» 1 Member(s) | 2610 Guest(s)
Avatar

>