Thread Rating:
  • 2 Vote(s) - 5 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco model 18 (code 121) - HELP!
#33

Not sure your question was answered, but there are tons of old Heathkit and Eico, etc... signal generators on Ebay, or whatever, that shouldn't cost more than $30 or so delivered. If you get one, you should treat it as an antique radio, change the filter and paper caps and any out of range resistors. Install a 3 prong cord, check your bench supply to make sure all is right, and lose any caps from line cord to chassis on the instrument.

Now get a modern digital frequency monitor, which you should be able to get for $20.00 or so, and you will be all set for AM radio work. Let the signal generator warm up for at least 30 minutes, then use the frequency meter to verify unmodulated signal generator output, disconnect the frequency meter, and restore modulation. Now you have pretty good means to do alignment. I like an analog AC voltmeter or VTVM across the secondary of the Audio transformer (with shunt resistor of say 4 ohms if you don't want to hear the noise.) A digital meter to peak during alignment will drive you crazy(ier.)

Usual warning, absolutely always use isolation transformer on AC/DC sets. Correctness of AC sockets in most places is sadly still not reliable.


Messages In This Thread
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-07-2013, 10:22 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-08-2013, 10:32 PM
RE: Philco model 18 (code 121) - HELP! - by Arran - 02-08-2013, 10:49 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-09-2013, 02:21 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-09-2013, 05:57 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-09-2013, 06:12 PM
RE: Philco model 18 (code 121) - HELP! - by codefox1 - 02-10-2013, 06:36 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-13-2013, 08:40 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-21-2013, 05:25 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-28-2013, 06:04 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 03-07-2013, 04:16 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 03-07-2013, 11:20 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-17-2013, 01:25 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-18-2013, 08:48 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-18-2013, 09:49 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-29-2013, 10:02 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 06-12-2013, 01:37 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 06-13-2013, 08:33 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 07-23-2013, 10:33 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 07-24-2013, 11:11 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 08-02-2013, 05:06 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 08-21-2013, 10:26 AM
RE: Philco model 18 (code 121) - HELP! - by morzh - 12-17-2013, 10:58 AM
RE: Philco model 18 (code 121) - HELP! - by morzh - 12-19-2013, 12:47 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 12-19-2013, 08:48 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 01-17-2014, 04:05 PM



Users browsing this thread: 56 Guest(s)
[-]
Recent Posts
Philco 16B Parts
The 16B's in the tombstone cabinet sport a 10 1/2" spkr vs the older cathedral sets which uses an 8". The p/p ...Radioroslyn — 12:58 AM
Philco 38-7 Oscillation
I have let this one sit because of other duties. Now I am back, and I have a couple of questions. I hooked up a Hammond ...tludka — 11:16 PM
Philco 38-7 Speaker
I know that when I first started working on this radio, I did not even have a speaker. Once I finally found one it was n...tludka — 11:00 PM
Philco 60 Squealing
I seem to remember eliminating a squeal by changing the IF frequency by a few KHz. Not that you should put too much tru...fenbach — 08:48 PM
Philco 42-390, code 121 speaker
These speakers pop up on eBay regularly, even if at bloated prices. Honestly, have not seen many parts on swapmeets.morzh — 08:38 PM
Philco 38-7 Speaker
The put-put is not like the speaker problem.morzh — 08:29 PM
Mission Bell Model 19A Car Radio
Hello everyone,  As mentioned in my last post I was going to see if the vibrator / rectifier section could be persuaded...Antipodal — 08:21 PM
Philco 60 Squealing
Wondering if I did it backwards. If a coil was wound backwards, the oscillator would not work at all. Old school...Chas — 07:23 PM
Philco 38-7 Speaker
4-ohm speaker. Black, Green leads.tludka — 07:00 PM
Philco 42-390, code 121 speaker
#87 on the schematic.  This radio had a 8" Zenith  speaker attached to it when I got it. I do don't know the hist...Stevelog — 06:39 PM

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

>