UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Hints, Tips and Solutions (Do NOT post requests for help here)

Notices

Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

Closed Thread
 
Thread Tools
Old 13th Oct 2003, 6:31 pm   #1
JHGibson
Retired Dormant Member
 
Join Date: Apr 2003
Location: Salt Spring Island, BC, Canada
Posts: 368
Default "Rebuilding" a Rectifier Valve

The UU2 rectifier in my Ultra AC "Blue Fox" had an internal open connection although the filament was good. As this valve and its equivalents are rather rare and expensive when found, I decided to "repair" the old one.

Its envelope to base glue joint was loosened by boiling it for 20 minutes in a saucepan. The solder in the pins was melted and extracted with a sucker tool, and the internal wires were freed up with the aid of a jewellers screwdriver and the base removed.

The anode wires were clipped off and the filament wires extended a few inches, making sure that the joint was twisted and soldered compactly enough to slip through the base pins. Suitable lengths of insulating sleeving were slipped on.

The valve's twin diodes were substituted for by two 2KV PIV 1A silicon diodes, each with a half watt 100 ohm resistor in series. These were tucked into the inside corner of the base and connected to the original anode and cathode pins while observing correct diode polarity. The two filament wires were threaded through the appropriate pins and the glass envelope drawn into place. All wires were drawn tight and soldered to the pins.

The glued joint was remade by first warming up the valve in an oven at a low setting, and then applying two part slow setting epoxy adhesive. The warm base permitted the glue to flow easily into the joint. After wiping excess glue off with tissue, the glue was allowed to set overnight.

The rectifier now looked completely original and worked fine when replaced in the Ultra and it was a delight to see the valve filament light up still.

P.S. Someone is going to get a surprise a hundred years from now when they check the emission of this rectifier!

Last edited by Paul Stenning; 27th Dec 2004 at 12:05 am. Reason: Fix link or code for vBulletin
JHGibson is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 2:00 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.