The PHILCO Phorum
Peerless Radio Find - Printable Version

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RE: Peerless Radio Find - WallaceRoger - 05-17-2017

If you compare the photos of the Clinton and the Silver, the knobs are the same (except the Silver looks like it has a different one at the far right). My guess is yours had the same round knobs and someone swapped them at some point.

By the way, here's yet another re-badge of your radio, this one sold as a Phillips

https://s-media-cache-ak0.pinimg.com/236x/21/97/8f/21978f704bb74ebcf59da049c9f760a5.jpg

RE: Peerless Radio Find - OZ4 - 01-08-2021

I decided it's time to post something new. 

Here's a follow up on the mods to the not so desirable circuit design of this Peerless/Clinton 139. First is the original detector design.        So because there is no AVC the volume goes all over the place. I am thinking can I add AVC to this circuit without too much grief. 

Now here' are the mods. The the detector, the ballast resistor, and the filter cap. 

The detector circuit is from a Philco 40-140 with AVC. I cheated and used germanium diodes and reused the 76 tube as a just audio preamp. So the AVC works fair. I attached to where the ground was for the first antenna coil is.  It only varies the first RF stage gain. I also added a filter cap to the bias voltage for the 76 tube.

I know I used too big a filter cap at the rectifier. So I am thinking I will add series resistor with the large cap. This should lower the peak rectifier current and still keep the ripple hum down.

And last is the ballast resistor. I replaced it with an 8uf motor run cap. It took a few tries to find just the right value. I measured the filiment voltage of the 25Z5 tube for this. It takes a little longer to warm up but it works with no resistor heat. 

I made these mods some time ago. And still need to add the series resistor to the rectifier cap. I will try and post the results.

RE: Peerless Radio Find - morzh - 01-08-2021

I doubt that resistor was original. I think it was someone's mod to replace the CB cord.
8 uF sounds about right. This is what I used in AA5s with CB cords.

RE: Peerless Radio Find - Radioroslyn - 01-08-2021

You could if wanted SS the 25Z5 by using an old base and adding 3 diodes. One across the heater pins and the other two the plate to cathode. No heat and more B+++++++. I've used it in a few sets but not w/a cap dropper

GL w/your project!

RE: Peerless Radio Find - OZ4 - 01-08-2021

Today I changed the first filter cap from 450uf to 33uf this should lower the peak rectifier current.  Then redrew the power supply so it made sense.

 I also drew in the ground at the 6A7 cathode where it use to have the volume control attached to it. 

I also decided that it had too much audio gain after changing the 76 tube from detector to audio amp.  and added some resistors to the volume control. I know I could have added a resistor the the 76 cathode and may try this instead. 

 After looking closer at the power supply I moved the power switch to hot side of the cord with a 2 amp fuse and made sure the neutral side went to the chassis part of the bias circuit. (it's a polarized plug) Now I only have 10vac from the chassis to earth ground.    

RE: Peerless Radio Find - Simon Wa3uay - 01-09-2021

this thread will come in very handy, as we have one too!  But it's a 'GENERAL'