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

40-195 Restoration
#46

It looks like part #12, an RF choke connected across a 10k resistor to the plate of the 1232 tube. The other end would be connected to another resistor and a 100pf cap.
#47

Makes sense, thank you Rod.
#48

Question, what does it mean "use loop on generator" in the instructions attached?

       

Also, which one of these instructions should I use for a 40-195?

Thanks in advance!
#49

Create a loop antenna transmitter with a coil of about 5-6 turns of wire 4-6 inches in diameter and connect the hot side of your signal generator to one end. You now have a radio transmitter that varies the radio reception signal strength by how close it is to the receiver.

The second set of instructions can be used for the 40-195 alignment (note upper right corner).
#50

I see, thank you for the clarification Rod as this is a new procedure for me. 

One question is does it also need a ground on the signal generator?
#51

Normally no. The loop is small enough to be a short and usually reduces the signal output. But you can always try an earth ground on the other end of the loop just to note the effect.
#52

Rod, 

Connecting the loop to the output and tuning the signal generator to the same wavelength as the radio, say 580khz, I should hear a tone from the SG on the radio?

If not, what am I doing wrong?
#53

Where are you in the alignment procedure? Make sure the band switch is on broadcast.
#54

Operation 1 was successful connecting to terminal 1 on the back of the radio using a .1mfd inline and the ground to the chassis. 

Operation 2 is iffy where the signal does not seem to be very strong if at all. 

Operation 3 seems to work. 

Now to qualify something, under Connecting Aligning Instruments, I am not removing the tubes and replacing with an aligning adapter. I am not sure what it even is.

 
.pdf Aligning.pdf Size: 62.31 KB  Downloads: 186
I found this document for aligning Philco's which seemed easier to follow but still not much luck.
#55

I should mention that I am using an Eico 330 signal generator that seems to be in working order.
#56

I'm not sure what the aligning adapter is but I can guess. I would say it gives you the capability to use a test meter of lower ohms-per-volt to measure the AVC voltage. Meters of the day would "load" a circuit and indicate a false reading. Using a high impedance DMM or VTVM will have very little impact on the AVC voltage providing it is connected to the high side of the volume control.
#57

I am looking for some guidance with how to go through and validate voltages on the tube pins. I thought I saw someone post something with the tubes and pinnings but I am not positive.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum Martin. I count about 9 paper caps, the 3 electrolytic caps and 2-Y2 safety caps to replace th...RodB — 09:44 PM
Part numbers to model cross
Jim, We have this index put together by Dale Cook but I don't think that is quite what you are looking for. The Parts...klondike98 — 09:37 PM
Philco Model 38-7: what caps & resistors do fail typically?
Yep the dim bulb test is OK but I'd definitely replace all those electrolytics before I did it. Since those #47 conden...klondike98 — 09:18 PM
Philco 42-345 Restoration/Repair
The resistor is a 2.2 Meg, it was the last one I hadn't replaced. The broadcast is coming in after replacing it.osanders0311 — 09:09 PM
Philco 42-345 Restoration/Repair
What does the resistor measure? I think it should be 3.3 Meg. If the oscillator coil has continuity and the resistanc...RodB — 09:03 PM
Philco Model 38-7: what caps & resistors do fail typically?
Good idea to check the coils... then I'll get hold of an incadescent light bulb and see what happens when the unit is sw...Musaeum — 08:49 PM
Philco 42-345 Restoration/Repair
I have that same set, ain't too much shortwave I like anyway.....it is a good AM DX set. PaulPaul Philco322 — 08:32 PM
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum, Martin! Open a new thread in Philco Electronic Restoration when you begin working on your 38-7. ...GarySP — 08:28 PM
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum! :wave: Here's the schematic for that radio from our digital library: Something to do bef...klondike98 — 08:05 PM
Philco Model 38-7: what caps & resistors do fail typically?
Hi all, on vacation in Montreal,  a friend of mine showed me a Philco Model 38-7 console radio from the 30ies. Mechan...Musaeum — 07:21 PM

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

>