The Pilot T601 Restoration Saga - UK Vintage Radio Repair and Restoration Discussion Forum

markfff · 3rd Sep 2023, 7:25 am

Last year I picked up an FM Tuner at a thrift store. It was kind of a plain looking thing, but for $10 I couldn't pass it by. This turned out to be a pre 1949 Pilot model T601. Ulike many old wooden cabinet tube radios, the cabinet was in good condition, just a few scratches and a dulled finish. The main cosmetic issue for me was the faceplate cover (see this thread https://www.vintage-radio.net/forum/...d.php?t=188046). After repeated unsuccessful attempts to form a new cover, I gave up and put the tuner on the shelf for later.

Now it's later and I had another go at it. This time I stripped and refinished the cabinet, then found there was just enough clearance to install a flat faceplate cover. I know you purists out there like the old yellowed patina, but it wasn't working for me. I did store the original cover inside the cabinet for possible future use.

With the cabinet done, on to the chassis. I replaced all of the wax caps, then pulled the electrolytic, a 4 section can under the chassis, to test and reform it. Two of the sections were unsalvageable, so I replaced the can with four new 'lytics. After a little cleanup on the top of the chassis (not much was needed) I powered it up and plugged it into an amp. Not only did it work, but it sounded great.

Being very pleased with myself, I reassembled everything into the cabinet, hooked it back up, tuned it a classic rock station and sat back listening, happy as a clam. But a half hour in there was a loud bang, a cloud of smoke and 60Hz emitted loudly from the speakers. I got everything working again yesterday and it sounds great again, I have been listening for hours, even as I write this.

I had assumed the mica caps would be ok -wrong. One connected from line to ground (C28) had shorted, dumping ac onto the chassis before splitting open and releasing its smoke. The 120 volts, looking for the easiest path to ground, went through the amp and blew out the pcb ground trace in three different places. C28 was a .01 uf from ac to ground, and I just removed it without replacing. Grounded line filters are an idea I don't much care for anyway, I feel they're often not necessary, and potentially unsafe, but if anyone begs to differ please speak up.

Mark

vinrads · 3rd Sep 2023, 9:32 am

Hi Mark what a lovely little thing, looks fantastic I am with you regarding the dial cover, shame it damaged your amp, nice to see the full coverage of the VHF FM band.

Mick.

ms660 · 3rd Sep 2023, 11:52 am

The capacitor will be paper not mica.

Micamould made both paper and mica capacitors in that type of encapsulation.

Lawrence.

Sideband · 3rd Sep 2023, 7:28 pm

The radio will work without the filter caps but if you want to replace, use a proper designed-for-the-job Y capacitor (line to ground).

3rd Sep 2023, 7:25 am	#1
markfff Tetrode Join Date: Aug 2021 Location: Virginia Beach, Virginia, USA Posts: 79	The Pilot T601 Restoration Saga Last year I picked up an FM Tuner at a thrift store. It was kind of a plain looking thing, but for $10 I couldn't pass it by. This turned out to be a pre 1949 Pilot model T601. Ulike many old wooden cabinet tube radios, the cabinet was in good condition, just a few scratches and a dulled finish. The main cosmetic issue for me was the faceplate cover (see this thread https://www.vintage-radio.net/forum/...d.php?t=188046). After repeated unsuccessful attempts to form a new cover, I gave up and put the tuner on the shelf for later. Now it's later and I had another go at it. This time I stripped and refinished the cabinet, then found there was just enough clearance to install a flat faceplate cover. I know you purists out there like the old yellowed patina, but it wasn't working for me. I did store the original cover inside the cabinet for possible future use. With the cabinet done, on to the chassis. I replaced all of the wax caps, then pulled the electrolytic, a 4 section can under the chassis, to test and reform it. Two of the sections were unsalvageable, so I replaced the can with four new 'lytics. After a little cleanup on the top of the chassis (not much was needed) I powered it up and plugged it into an amp. Not only did it work, but it sounded great. Being very pleased with myself, I reassembled everything into the cabinet, hooked it back up, tuned it a classic rock station and sat back listening, happy as a clam. But a half hour in there was a loud bang, a cloud of smoke and 60Hz emitted loudly from the speakers. I got everything working again yesterday and it sounds great again, I have been listening for hours, even as I write this. I had assumed the mica caps would be ok -wrong. One connected from line to ground (C28) had shorted, dumping ac onto the chassis before splitting open and releasing its smoke. The 120 volts, looking for the easiest path to ground, went through the amp and blew out the pcb ground trace in three different places. C28 was a .01 uf from ac to ground, and I just removed it without replacing. Grounded line filters are an idea I don't much care for anyway, I feel they're often not necessary, and potentially unsafe, but if anyone begs to differ please speak up. Mark Attached Thumbnails

3rd Sep 2023, 9:32 am	#2
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,766	Re: The Pilot T601 Restoration Saga Hi Mark what a lovely little thing, looks fantastic I am with you regarding the dial cover, shame it damaged your amp, nice to see the full coverage of the VHF FM band. Mick.

3rd Sep 2023, 11:52 am	#3
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: The Pilot T601 Restoration Saga The capacitor will be paper not mica. Micamould made both paper and mica capacitors in that type of encapsulation. Lawrence.

3rd Sep 2023, 7:28 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,580	Re: The Pilot T601 Restoration Saga The radio will work without the filter caps but if you want to replace, use a proper designed-for-the-job Y capacitor (line to ground). __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....