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 70 air cap ground strap.
#14

You guys hit with the capacitance on the strap.
I've been through several windings on the osc.
and det. coils to experiment, and could struggle
to get a 'decent' sound, it was unstable, esp.
volume wise. I went with 32g on the oscillator
last night, still something not right. This morning
I removed the air cap and switched the osc. connection
to the other side with the brass washer, and then screwed
the strap back with the insulated washer.
A real pain. All back together and what a difference,
everything changed, sound much smoother, can hear exactly
what the trimmers are doing and can push up the
volume with stability. Still don't know what hooking up
the other way was doing, but the chassis hole lines up
with the right side screw, should have been a clue.
Probably all my windings would have been acceptable, a forgiving radio,
just find the IF you end up with. I used plain old
Pen Gear Matte Finish invisible (scotch) tape wrapped
to the thickness of the original celluloid with 32G wrap
on top for the RF osc. coupling. Is it heterodyning the original way, no, but acceptable.
It does a strange thing, after around 5 minutes of playing is suddenly dies, and have to tune several KHZ down
to get it back, and the sound is not quite as loud and good, maybe a tube, the 27 is getting weak. It's a fun twiddle machine.


Messages In This Thread
Model 70 air cap ground strap. - by radio1 - 06-10-2020, 08:43 PM
RE: Model 70 air cap ground strap. - by rfeenstra - 06-11-2020, 08:38 AM
RE: Model 70 air cap ground strap. - by radio1 - 06-11-2020, 09:39 AM
RE: Model 70 air cap ground strap. - by radio1 - 06-12-2020, 05:17 PM
RE: Model 70 air cap ground strap. - by radio1 - 06-12-2020, 07:01 PM
RE: Model 70 air cap ground strap. - by rfeenstra - 06-12-2020, 11:20 PM
RE: Model 70 air cap ground strap. - by radio1 - 06-13-2020, 07:39 PM
RE: Model 70 air cap ground strap. - by radio1 - 07-02-2020, 08:21 PM
RE: Model 70 air cap ground strap. - by radio1 - 07-03-2020, 06:25 PM
RE: Model 70 air cap ground strap. - by radio1 - 07-03-2020, 06:42 PM
RE: Model 70 air cap ground strap. - by radio1 - 07-03-2020, 09:19 PM
RE: Model 70 air cap ground strap. - by radio1 - 07-04-2020, 07:11 AM
RE: Model 70 air cap ground strap. - by rfeenstra - 07-04-2020, 09:06 AM
RE: Model 70 air cap ground strap. - by radio1 - 08-13-2020, 06:13 PM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco 49-1040
I thought I had an arrangement to restore this set for a customer but his wife said heck no.  Instead, he gave it to me....Bob Andersen — 10:29 PM
Philco 46-480 Electronic Restoration
I kept working on reassembly this week. I wasn’t able to solder for a few days while it was too cold (single digit low t...jrblasde — 09:27 PM
Atwater-Kent 84, restoration.
Well, powering it up would be too good to be true, and I had that feeling. Before I did, I decided to check the coils...morzh — 06:02 PM
An attempt to remove the Field Coil from a G speaker
Thanks Chas, sure will give it a look!morzh — 03:39 PM
An attempt to remove the Field Coil from a G speaker
Mike, Lookup  murrayatuptown on ARF. Seems he has a dilemma with surplus field coils. Could get lucky and have what y...Chas — 01:26 PM
Atwater-Kent 84, restoration.
Hello Mike, I have not checked to see if my console has a fuse or not and far as sets go I have early 30s General Motor...radiorich — 11:25 AM
Atwater-Kent 84, restoration.
Ron I forgot, but when you said "phone number", I remembered, caus I usually remember how I act when I need...morzh — 11:12 AM
Atwater-Kent 84, restoration.
You have an extensive collection of Philcos, Mike! I’m always excited to see each new one. Agreed on the power supply fu...jrblasde — 10:50 AM
462ron
Hi Mike, that 84 sure looks great. You don’t often see these antique radios with a fuse like yours has. I usually instal...462ron — 10:22 AM
Atwater-Kent 84, restoration.
Hello Mike, Wow ! far as my AK it does work and the cabinet is in nice shape so is my chassis anyway here is a photo of...radiorich — 02:59 AM

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

>