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

Philco 39-45... help?
#10

Re: an AM transmitter. I actually use my HP3325A function generator as an AM transmitter if I need one. This is another reason I like to use it for my signal generator. With the A version you need a 2nd audio signal generator also.

The HP3325B (later version) actually has an internal modulation source also so you don't need the 2nd audio osc.

Before anyone spends very much on a dedicated AM transmitter you should look at getting a used 3325A or B instead. They are great for doing alignments and as a general purpose function generator. Can't beat
the totally accurate frequencies you get and complete accurate amplitude control

Re: Minimal experience with vintage tube electronics and lots of modern electronics experience. I was like that also to some degree but always grew up with tube stuff in my teen years so always had some knowledge of the older stuff. My knowledge has increased 100x in recent years as I work on these old radios.

Best advice is to be careful of the high voltages, get yourself a variac and a way of putting a light bulb in series with the line cord when you first do a power up.

Always replace old capacitors no matter what. Electrolytics and paper caps. Micas are probably good although not always.

You are taking a huge risk by leaving in old caps. If the wrong one shorts out then you can take out transformers or coils or who knows what and then you may or may not be able to fix it again.


Messages In This Thread
Philco 39-45... help? - by Dbwaibel - 01-29-2014, 03:02 PM
RE: Philco 39-45... help? - by tab10672 - 01-29-2014, 07:21 PM
RE: Philco 39-45... help? - by morzh - 01-29-2014, 08:59 PM
RE: Philco 39-45... help? - by Eric T - 01-29-2014, 09:06 PM
RE: Philco 39-45... help? - by BrendaAnnD - 01-29-2014, 09:10 PM
RE: Philco 39-45... help? - by Raleigh - 01-29-2014, 09:22 PM
RE: Philco 39-45... help? - by Raleigh - 01-29-2014, 09:35 PM
RE: Philco 39-45... help? - by Dbwaibel - 01-30-2014, 12:24 AM
RE: Philco 39-45... help? - by BrendaAnnD - 01-30-2014, 03:01 AM
RE: Philco 39-45... help? - by hsusmann - 01-30-2014, 09:26 AM
RE: Philco 39-45... help? - by Dbwaibel - 02-03-2014, 11:28 PM
RE: Philco 39-45... help? - by Raleigh - 02-04-2014, 12:05 AM
RE: Philco 39-45... help? - by Dbwaibel - 02-04-2014, 12:11 AM
RE: Philco 39-45... help? - by Dbwaibel - 02-04-2014, 12:31 AM
RE: Philco 39-45... help? - by skyscraper - 02-04-2014, 01:02 AM
RE: Philco 39-45... help? - by Dbwaibel - 02-04-2014, 08:43 PM
RE: Philco 39-45... help? - by morzh - 02-04-2014, 11:21 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
1930s Stewart-Warner Tombstone Radio need help identifying model number
UPDATE: I was able to pick up a signal generator on the cheap (amazingly enough) on feebay and I did an IF alignment fol...captainclock1988 — 09:53 AM
Philco 91 Schematic
Hi Rod, The resistor connects to pin 4 and the ungrounded side of block 9. From pin 9 of the RF tube to one side of ...dconant — 09:34 AM
Just got a 49-1613 need to know...everything!
I just found your post. I have this exact same model, and have had it since 1985 when I was 15 years old! I performed a ...MuzzcoVW — 09:11 AM
B&K 1077B no video
Hello Tim, I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ? Sincerely Richardradiorich — 01:55 AM
B&K 1077B no video
I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM
RCA 15X
I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM
B&K 1077B no video
Hello Tim, I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!. Sincerely...radiorich — 11:07 PM
RCA 15X
Everthing goes at once, maybe it's the cold weather, I have had 2 dial strings break and no my little RCA is having dial...Paul Philco322 — 10:26 PM
Philco 91 Schematic
Hi Dan, I can't explain this specific resistor but I have seen the use of a switch to apply B+ voltage to screen gri...RodB — 09:36 PM
6TPZ and 5TPO Radio Help
I suspect it's been repaired before. And I suspect whoever repaired it, wanted to re-use old transistors' pin stubs in o...morzh — 09:24 PM

[-]
Who's Online
There are currently 8385 online users. [Complete List]
» 1 Member(s) | 8384 Guest(s)
Avatar

>