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

my 4 tube battery set 39-70 has 5 tubes and an AC cord??
#21

First, let's start with a link to the schematic of the 39-70. http://www.nostalgiaair.org/PagesByModel...013302.pdf

First thing I see is that all the filaments were originally wired in parallel to ground rather than in series, so the first thing to look at is the way the filaments have been rewired. To do this properly, first let's look at the data on the tubes you have.

35Z3 AC rectifier... 50L6 audio output amp, replaces the original 1C5.... 12SA7 pentagrid converter would replace the 1A7 of the original... the 12SK7 is used as the IF amp in place of the 1N5... the 12Q7 is used as the 2nd detector, ist audio amp in place of the 1H5. You can find data on all these tubes here http://www.nucow.com/Free%20Tube%20Data%...20data.pdf

I will leave it up to you to check if the pinouts match, and how closely. Please keep us posed on the developments of this project. It is really interesting.


Messages In This Thread
RE: my 4 tube battery set 39-70 has 5 tubes and an AC cord?? - by mikethedruid - 10-30-2014, 08:00 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Model 80 Antenna Issue?
Thanks Gary and Rod.  I also found an article in the Philco Repair Bench under Service Hints and Tips, about installi...Hamilton — 12:32 PM
Model 80 Antenna Issue?
Hello Hamilton, here is a little information found in our Philco Radio Library at the bottom of the Home page. Hope it ...GarySP — 11:28 AM
Model 80 Antenna Issue?
I did as you suggested and touching the middle of the volume control did nothing so the coil has to be rewound. Any idea...Hamilton — 10:19 AM
1949 Motorola 5A9M
This would be the second portable in the "other radios" forum where I have a similar one in my collection. I h...Arran — 12:41 AM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hi PittsburgTost. The record changer looks like a Garrard or BSR (Likely Garrard). The spindles just pull out and pu...MrFixr55 — 11:57 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hello PittsburghToast , Welcome aboard and it looks like gary may have something for you ! now if I dig through my se...radiorich — 11:35 PM
Model 80 Antenna Issue?
You are kind of on the right path. You can touch the grid cap of the Detector/Oscillator 36 tube. I'm expecting a respon...RodB — 08:48 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Welcome to the Phorum, PittsburghToast!  I found an old thread that my interest you regarding the quality and worth of P...GarySP — 08:48 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Welcome to the Phorum! :wave: We do not have anything on that unit in our digital library. There is a Sam's Photof...klondike98 — 08:47 PM
Model 80 Antenna Issue?
I’ve replaced all the caps and resistors and the radio is working but minimal volume unless I put my hand near the re...Hamilton — 08:24 PM

[-]
Who's Online
There are currently 1476 online users. [Complete List]
» 2 Member(s) | 1474 Guest(s)
AvatarAvatar

>