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

Model 60 Blues
#1

I'm new here.Howdy. I have a model 60(late style wiring) and did the recap, including bakelites, all out of spec. resistors, coil resistance check, etc.Broadcast band is fine, sharp peaking on IF cans, all seems well over the band.HOWEVER, the "police band" is dead,dead, dead.I cant find the reason.Antenna coil primary was open and I wound (in the right direction)with #30 and matched the resistance to the drawing.Other coils appear fine.I even have another chassis that I compared with.Checked the mica trimmers, bandswitch,etc. All SEEMS fine, but I need a Philco expert (Mr. Rameriz) to sort me out.
Thanks,
Tom[/b]
#2

Sounds like you have all the bases covered Tom with your restoration, but you will not hear Police transmissions on 30s and 40s sets that have this AM "Police" band.

That small segment of the AM band just above the regular band (1600-1750 or so) used to be the original Police band back in the 30s and 40s. Now Police are in the VHF and UHF bands with scrambled narow-band FM transmissions.

That band is now part of the expanded AM band (1610-1710). Depending on your area you may hear next to nothing, or occasionally one of the new expanded AM band stations in this newer X-band, as it's called.

Chuck

(One of the other Philco experts. Icon_smile )
#3

Thanks, Chuck.
I know nothing is on 1650 kc. or up a ways, but the band on the 60 goes from 1500khz -4mhz., and even with a signal generator cranked, there is nothing.However, if I turn on a work light with a dimmer, there is plenty of hash.
Tom
#4

Hi Tom, and welcome!

Sounds to me like your oscillator is not running on the "police" band. Did you rewind the oscillator coil primary? And if so, did you use the same number of turns, wound COUNTER-clockwise? The oscillator coil in the 60 is a bit more "finicky" than many other Philcos of this era. I have the specs for the number of turns for both coils around here somewhere (when I rewind a coil, I write down the number of turns and such for future reference).

The primary of both antenna and oscillator coils should be wound with 38 gauge wire; the secondaries (if needed) usually get 32 gauge. #30 would probably be O.K. for the secondary, but not the primary.

Check the band switch itself for possible dirt and corrosion. Deoxit is the best for cleaning these.

Another possibility is moisture absorption in your oscillator coil. You may have to remove it and literally bake it in the oven for about 1/2 hour at 200-225 degrees F. Models 19 and 89 are especially susceptible to moisture absorption in their oscillator coils, but it can happen to any set.

--
Ron Ramirez
Ferdinand IN
#5

Ron,
Thanks for the help. I did not rewind the osc. coil, since the resistance measured o.k., and it works well on the standard band.Maybe I will remove it and check for the corrosion problem you have mentioned on the website. Another guy said maybe the 6A7 is not able to osc. on the 1.5-4.0 mc. band. I'll substitute that first.
If I get it going I'll post the solution.
Tom
#6

Hi Tom,
Do you have a signal generator that you could set to a few test frequencys in that range and loose couple to the radios antenna? Also do you have a fairly decent lengh of wire attached for an antenna?

Just a few thoughts...........
#7

Jerry,
Yes I have a generator that I coupled thru a small capacitor.And for antenna,I tried my 75Ft. outside antenna,nada.
On a suggestion, I exchanged the 6A7 for another tube and got some signals on the low end of the 1.5-4 mc. band, so I think it may be the osc. coil,wire layout, or a 6A7 with internal capacitance or gain problems.
It is a strange one...
Tom
#8

Well guys, I'm back at it again. i put in a new 6A7, and checked everything again, now it works "gangbusters" on standard a.m., and works well on top end of other band, around 4 m.c., but no where else. I either can't make the osc. function or it won't track on the higher band.
Any new ideas? if not I'll put it back in the cabinet and forget it.
Thanks, Tom
Icon_cry




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
New Philco Repair Bench
I am sure this is the archive, and not the Chuck's site.morzh — 09:50 PM
Made mistake & did not label connection
It's not like we are good friends with that wire and can tell it from other ptetty identical looking wires. Why'n't you...morzh — 09:49 PM
Made mistake & did not label connection
I'm not sure why that wire wasn't covered in the video. I'm pretty sure the 6A8 won't work until that pin is grounded. Y...RodB — 09:47 PM
Made mistake & did not label connection
You'll have to forgive me, I am not sure what you mean.  Can you explain what you are really saying.  If anyone does not...georgetownjohn — 08:05 PM
Made mistake & did not label connection
Those are details better left to the ones who know. Maybe you disconnected the wrong end of the wire.RodB — 06:22 PM
Made mistake & did not label connection
Maybe this is starting to make some sense in my hard head.  Is this why the wire in question was not in the great Ron Ra...georgetownjohn — 04:34 PM
Made mistake & did not label connection
I was correct with the 6A8 pin connection's, 7 and 8 are connected to ground as well as the tube shield (the broken line...RodB — 02:41 PM
Made mistake & did not label connection
What does the dotted line representing that surrounds the tube in the schematic?georgetownjohn — 02:17 PM
Made mistake & did not label connection
Hello John, I have been there either label got lost or was not labeled ! Sincerely Richardradiorich — 02:15 PM
Made mistake & did not label connection
Sorry, it is a Philco 37-640.  Does that help?--Johngeorgetownjohn — 02:14 PM

[-]
Who's Online
There are currently no members online.

>