Posts: 674
Threads: 146
Joined: Jun 2011
City: Elko,MN.
Ok,Almost done,
Replaced the opt and the B+ is back to normal.
Have reception on 2 shortwave bands ad AM on pushbutton band.
But, nothing on broadcast band.
Cleaned band selector switch to no avail.
Other bands have good volume etc.
I am thinking broadcast coil is open? Where would I get one of those if that is the problem.
Otherwise works great.
Need to get this one done as my 4 grandkids are coming for a visit,and I need to to get this one out of the radio room.
Have to park it for a while I guess.
Any idea's?
Thanks guy's,
murf
(This post was last modified: 07-11-2014, 10:27 PM by murf.)
Posts: 403
Threads: 40
Joined: Feb 2011
City: McPherson, KS
Just jumping in late in the discussion for the first time but IF you have "AM on pushbutton band" you ought to have "broadcast band" working too because they are the same thing. Bad pushbutton switch?? Doesn't it switch from pushbutton mode to manual mode by a pushbutton? Dunno.
Posts: 674
Threads: 146
Joined: Jun 2011
City: Elko,MN.
Hi Art,
It has a seperate coil for each of the pushbuttons, as well as a seperate coil for the broadcast band.
Uses a band selector switch to switch from pushbutton tuning to manual tuning via the thumbwheel.
I tried to check the coil to see if any of the windings were open and could not really check one of the windings due to not being able to get to the leads.
Thanks for your help.
murf
Posts: 4,913
Threads: 54
Joined: Sep 2008
City: Sandwick, BC, CA
I will have to look up the diagram but in most Philcos they didn't bother using a dedicated tuned circuit for each pushbutton, they just used a pair of trimmers for each preset, one connected to the antenna coil, and the other connected to the oscillator coil. It's easy enough to check the broadcast band antenna coil, just use an ohm meter on the primary and the secondary, if it has continuity on both winding then the trouble is elsewhere. I would have a look though the front end of the radio and see if there are any burned looking coils related to the AM broadcast band, maybe the antenna was hit by lightening?
Regards
Arran
Posts: 674
Threads: 146
Joined: Jun 2011
City: Elko,MN.
Hi Arran,
So in other words, if I have AM reception in the pushbutton mode, the coil(#2) on the schematics, is ok?
Posts: 4,913
Threads: 54
Joined: Sep 2008
City: Sandwick, BC, CA
According to the schematic I have the BC antenna coil is labeled as part #2, they call it a transformer on the parts list, this is in addition to the loop antenna. The pushbutton bank has coils but they are switched into the BC band oscillator circuit when part #17, the BC and Police oscillator coil is switched out. There must be a position on the band switch for pushbutton tuning, if the bandswitch is on standard broadcast the pushbuttons will not work, if the bandswitch is on pushbutton the dial tuning will not work. It's possible that the BC oscillator coil might be open, or burned out, I would check the primary and secondary with your ohm meter, the primary is lugs 1, 2, and 3, secondary is 4, 5, 6 and 7.
Regards
Arran
Posts: 674
Threads: 146
Joined: Jun 2011
City: Elko,MN.
That's right.
Bandswitch controls pushbuttons and broadcast band. They are separate positions.
Get am reception on a couple strong stations using pushbutton presets, but nothing on broadcast band.
Will see if I can find the BC osc. coil and ohm it out tonight.
Thanks Aaran.
murf
(This post was last modified: 07-16-2014, 09:36 PM by murf.)
Posts: 674
Threads: 146
Joined: Jun 2011
City: Elko,MN.
Found both coils were bad.
Replaced with a couple donors from John's chassis and we are working great now.
Thanks everyone.
murf
Posts: 152
Threads: 11
Joined: Feb 2013
City: Dallas, TX
So murf.. the oscillator coil was bad? mine's kinda iffy.. I had a heck of a time aligning mine.
hard to find one of those having the 7th lug.. lucky thing you had a donor!
will be interesting to hear if you can tell a difference between the push button and dial tuning. when I have mine on the push buttons the tone isn't as nice or deep as it is on the dial.
Posts: 674
Threads: 146
Joined: Jun 2011
City: Elko,MN.
Guess I don't notice a difference in tone.
Replaced the osc. coil and the antenna coil. Both were open.
Thanks to John, we got it playing again.
murf
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