Atwater Kent 35 AC power supply issue

Questions and answers about repairing the inner workings of radios/phonos. Ads are not permitted.
Post Reply
ettore
Member
263
Nov Sat 24, 2012 4:05 am
Forest Lake, MN 55025

Atwater Kent 35 AC power supply issue

Post by ettore »

Greetings all, I have finished restoring my AK 35. I am now trying to make it operate. I am using a K-101A Regulated A, B & C Battery Eliminator Kit I bought and assembled a few years ago from "Antique Electronic Supply" (tubesandmore.com). I am attaching photos of the layout and the schematic.

When I hook the radio up it comes to life but appears to produce a very loud and noticeable 60 cycle hum out of the AK E3 speaker I have hooked to the radio. However, I can only pick up one very strong station but very weakly. I have the radio connected to 40 foot long wire antenna and to a metal stake in the ground for the ground. The volume control seems to work fine and I can physically see it vary the filament brightness. I tried reversing the plug but no change. I have used this Battery Eliminator on an old battery operated Coronado with no issues.

I then tried my old Brandes 1,000 ohm headphones. With headphones connected and the radio turned OFF when I plug my Battery Eliminator in I can hear a faint 60 cycle hum in the headphones almost like the Battery Eliminator is inductively connect to my headphones. When I turn the radio on the 60 cycle hum in the headphones is deafening.

Does this Battery Eliminator unit need capacitors across the AC line to send the 60 cycle to ground, if so I am not sure where to install them that's why I have included a copy of the schematic, or am I stuck with trying to use a battery setup?

Any help or thoughts would be greatly appreciated.
ettore
Attachments
LnaqN%jhTMueAFxZ7fsIWA.jpg
vzrukJ4bSYumLiu+MGeLWw.jpg
lostcauses10x
Member
2383
Feb Mon 25, 2013 2:39 am
Truth or Cosequences, NM

Re: Atwater Kent 35 AC power supply issue

Post by lostcauses10x »

How many years ago?
As with all electronics them electrolytic capacitors may be a problem
ettore
Member
263
Nov Sat 24, 2012 4:05 am
Forest Lake, MN 55025

Re: Atwater Kent 35 AC power supply issue

Post by ettore »

Thanks had not thought they could be bad being only 3-4 years old. Cheap fix though will try.
ettore
ettore
Member
263
Nov Sat 24, 2012 4:05 am
Forest Lake, MN 55025

Re: Atwater Kent 35 AC power supply issue

Post by ettore »

Here is a better schematic photo.
ettore
Attachments
WMTiGEVAQ1ChLXfduHM+hQ.jpg
ettore
Member
263
Nov Sat 24, 2012 4:05 am
Forest Lake, MN 55025

Re: Atwater Kent 35 AC power supply issue

Post by ettore »

Electrolytic Cap C1 for the B+ was totally dead. Put in a new one and swapped out the 301A audio tube for a 71A bumped the C- up to -12 volts and the radio plays wonderfully. Thanks for the suggestion to check the EC's on the Battery Eliminator, I would have never thought to do that because of the newness of the components. Now it is on to trying to resurrect my AK 55C thanks for all the help all.
ettore
lostcauses10x
Member
2383
Feb Mon 25, 2013 2:39 am
Truth or Cosequences, NM

Re: Atwater Kent 35 AC power supply issue

Post by lostcauses10x »

Welcome to shelf life of components.
I have a stash that never used, going on 10 years. Time to chunk em and just order what I need
jrehkopf
Member
3442
May Sat 30, 2015 10:49 pm
Keystone Heights, FL 32656

Re: Atwater Kent 35 AC power supply issue

Post by jrehkopf »

ettore wrote:Electrolytic Cap C1 for the B+ was totally dead.
Can you be more specific. What do you mean by "dead"?
Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter
brnhornet52
Member
2444
Jan Thu 01, 1970 12:00 am
Bristol TN 37620

Re: Atwater Kent 35 AC power supply issue

Post by brnhornet52 »

Good job, Ettore
ettore
Member
263
Nov Sat 24, 2012 4:05 am
Forest Lake, MN 55025

Re: Atwater Kent 35 AC power supply issue

Post by ettore »

The C1 Electrolytic for the B+ power of my Battery Eliminator is suppose to be 47uf. I checked the EC on my ECG Capacitance Meter and it read 0. I did have the EC cut out of the circuit when I checked it. Put a new EC in and everything works great.
ettore
User avatar
Chas
Member
21153
Jan Thu 01, 1970 12:00 am
S. Dartmouth MA USA

Re: Atwater Kent 35 AC power supply issue

Post by Chas »

...and it read "0".
Broken internal connection, does happen, seen on resistors and may occur on any device.
Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
ettore
Member
263
Nov Sat 24, 2012 4:05 am
Forest Lake, MN 55025

Re: Atwater Kent 35 AC power supply issue

Post by ettore »

Thanks I was baffled also but you never know what will happen.
ettore
You must be register and login to post a reply.
Post Reply