Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

37-640 bandswitch ?
#18

Thanks Greg, your reassurance of using parts from the 620 is very helpful.  Since I am still new at all this, I will wait til the 620 chassis arrives before I start taking the 640 RF unit out and apart.  I still have the wires in the 640 labeled/numbered from the original restoration attempt so I am hoping the wiring layout is similar in the 620.  If I remember correctly, while taking the 640 RF/tuner section apart for the recapping, there are 3 divided sections similar to bulkheads on a ship.  The dividers are L shaped at the top and screw up into the top of the chassis.  If I am lucky, I will try to just remove the divided section that has the bandswitch and recap any caps in that section while I am at it.  Regards to all, --John
I do have 2 additional questions that you may be able to help with.
First, why does the 620 onl show 3 wires to the speaker while the 640 uses 4 wires.  Does it have anything to do with the fact that the 640 has push-pull amplificaton and the 620 does not? 
Second, I have read where Philco was notorious for making errors in part numbers.  So I wonder if I can still use the tuning capacitor from my 640 regardless of the bandswich I will use.  The front of my 640 tuner bracket capacacitor has 640 stamped on it from the factory but the part numbers for the tuner are different for the 620 vs the 640 in the respective parts lits!


Messages In This Thread
37-640 bandswitch ? - by georgetownjohn - 01-18-2025, 01:15 PM
RE: 37-640 bandswitch ? - by RodB - 01-18-2025, 02:19 PM
RE: 37-640 bandswitch ? - by morzh - 01-18-2025, 03:52 PM
RE: 37-640 bandswitch ? - by georgetownjohn - 01-18-2025, 05:12 PM
RE: 37-640 bandswitch ? - by morzh - 01-18-2025, 07:05 PM
RE: 37-640 bandswitch ? - by morzh - 01-18-2025, 07:53 PM
RE: 37-640 bandswitch ? - by RodB - 01-18-2025, 08:51 PM
RE: 37-640 bandswitch ? - by georgetownjohn - 01-19-2025, 11:00 AM
RE: 37-640 bandswitch ? - by morzh - 01-19-2025, 01:13 PM
37-640 part IDd - by georgetownjohn - 01-19-2025, 03:40 PM
RE: 37-640 bandswitch ? - by Greg - 01-19-2025, 05:24 PM
RE: 37-640 bandswitch ? - by Greg - 01-20-2025, 12:06 AM
RE: 37-640 bandswitch ? - by Greg - 01-20-2025, 01:59 PM
RE: 37-640 bandswitch ? - by georgetownjohn - 01-20-2025, 02:53 PM
RE: 37-640 bandswitch ? - by georgetownjohn - 01-20-2025, 02:57 PM
RE: 37-640 bandswitch ? - by Greg - 01-20-2025, 03:40 PM
RE: 37-640 bandswitch ? - by georgetownjohn - 01-20-2025, 04:36 PM



Users browsing this thread: 9 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
Hello Peter, Thank you for posting that !! Sincerely Richardradiorich — 09:40 AM
Eico 232 VTVM Schematic
It's a microwave antenna. ?;-p?. I substituted 1N4002s off the 6.3 vac winding for the 1.5 volt battery. Uniprobe is the...RodB — 05:50 PM
Eico 232 VTVM Schematic
Try BAMA for a schematic. Looks like a replacement power source for the D battery has been installed. The tube may be...Chas — 04:51 PM
Eico 232 VTVM Schematic
Is that a battery holder?morzh — 04:43 PM
Eico 232 VTVM Schematic
A friend gave me this Eico 232 VTVM and I'm having trouble locating the schematic for it. This one seems to be a later v...RodB — 04:17 PM
Var resistor id
Considering what it is in series with, I doubt there should be any power requirements. Of course, we should know wher...morzh — 03:23 PM
Var resistor id
Trim pot, about 1/2 watt part of focus divider. As stated 2k ohms. This appears to be a rusty chassis, resolder all ...Chas — 03:19 PM
Var resistor id
Its a Sylvania 400 oscilloscope. here is a clip of r-100. Would be nice to know the current required. Not listed in part...Martinj — 02:10 PM
The list of my radio & TV collection!
Thanks Richard. I hope you enjoy it. Here I have created an English section on the history of radio with videos in Engl...RadioSvit — 10:23 AM
The list of my radio & TV collection!
Hello RadioSvit, first all happy new year ! I will watch your new videos this week. Sincerely Richardradiorich — 09:19 AM

[-]
Who's Online
There are currently 5741 online users. [Complete List]
» 2 Member(s) | 5739 Guest(s)
AvatarAvatar

>