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

Model 80 Compact alignment
#2

Hello all,

Here is the rundown. While waiting for parts I swept the RF, LO and IF tuned circuits. Normally I can thet the allignment about 90% this way. On this radio the IF is published as both 450 and 460 khz. As found the IF on this one could not be tuned there. The caps simply would not go low enough in value. About the middle of the useful range put the IF at about 250 khz. The RF and LO could be adjusted 455 khz apart but it was all the adjustments could do. Assuming the IF of 250 khz I went ahead and alligned the radio and it works fine, quite well actually. The bottom half of the band is pretty quiet. Our most powerful stations are in the top half so I am not sure this is a problem. I am thinking the next step is to use the signal generator and check the sensitivity across the band. One possibility is that the RF and LO are diverging toward the bottom of the band. I'll do some checking.

The big question is the accuracy of the published IF frequency. Has anyone alligned one of these to 455 khz IF or seen a published IF in the 250 khz range? Any enlightenment would be appreciated.

keithw


Messages In This Thread
Model 80 Compact alignment - by barshnik - 06-25-2013, 03:31 PM
RE: Model 80 Compact alignment - by keithw - 06-25-2013, 03:53 PM
RE: Model 80 Compact alignment - by 7estatdef - 06-25-2013, 05:57 PM
RE: Model 80 Compact alignment - by keithw - 06-25-2013, 06:37 PM
RE: Model 80 Compact alignment - by 7estatdef - 06-25-2013, 09:36 PM
RE: Model 80 Compact alignment - by keithw - 06-25-2013, 11:05 PM
RE: Model 80 Compact alignment - by BrendaAnnD - 06-26-2013, 12:11 AM
RE: Model 80 Compact alignment - by keithw - 06-26-2013, 12:26 AM
RE: Model 80 Compact alignment - by BrendaAnnD - 06-26-2013, 01:15 AM
RE: Model 80 Compact alignment - by Arran - 06-26-2013, 01:38 AM
RE: Model 80 Compact alignment - by keithw - 06-26-2013, 08:49 AM
RE: Model 80 Compact alignment - by Ron Ramirez - 06-26-2013, 10:44 AM
RE: Model 80 Compact alignment - by keithw - 06-26-2013, 11:19 AM
RE: Model 80 Compact alignment - by Ron Ramirez - 06-26-2013, 11:47 AM
RE: Model 80 Compact alignment - by keithw - 06-26-2013, 12:17 PM
RE: Model 80 Compact alignment - by Ron Ramirez - 06-26-2013, 12:27 PM
RE: Model 80 Compact alignment - by Mondial - 06-26-2013, 01:48 PM
RE: Model 80 Compact alignment - by 7estatdef - 06-26-2013, 06:05 PM
RE: Model 80 Compact alignment - by Ron Ramirez - 06-26-2013, 06:55 PM
RE: Model 80 Compact alignment - by keithw - 06-26-2013, 09:40 PM
RE: Model 80 Compact alignment - by barshnik - 06-26-2013, 10:35 PM
RE: Model 80 Compact alignment - by keithw - 06-27-2013, 12:12 AM
RE: Model 80 Compact alignment - by Ron Ramirez - 06-27-2013, 05:09 AM
RE: Model 80 Compact alignment - by morzh - 06-27-2013, 09:23 AM
RE: Model 80 Compact alignment - by keithw - 06-27-2013, 09:33 AM
RE: Model 80 Compact alignment - by barshnik - 06-27-2013, 10:30 PM
RE: Model 80 Compact alignment - by codefox1 - 06-28-2013, 08:06 AM
RE: Model 80 Compact alignment - by 7estatdef - 06-29-2013, 06:26 PM
RE: Model 80 Compact alignment - by keithw - 07-16-2013, 10:53 PM



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.

>