Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st December 2009, 12:40 PM   #1
diyAudio Member
 
Join Date: Apr 2008
Default Armstrong 523 tuner problem

I have been trying to repair an Armstrong 523 FM/AM tuner for a friend. The tuner is at least 40 years old. Mono reception is fine, but in Stereo mode the pilot light illuminates, implying that a stereo signal is present, but the audio remains in mono, with a faint 'chuffing' noise in the background. This noise stops when mono mode is selected.

Compared with modern tuners using IC's, the decoder circuit, which lives on a separate PCB, seems very simple, with only 4 or 5 transistors. I have tested every component and nothing appears to have failed. The owner of the tuner has suggested that the decoder is based on a Mullard standard circuit, but I have been unable to unearth either this or a diagram for the tuner on the web. Can anyone offer any suggestions?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sont STR-6800SD Tuner Problem zedrider Solid State 1 18th October 2007 03:45 AM
Yamaha RX-V490.. Tuner problem tharakag Solid State 7 5th September 2007 08:47 PM
Problem with Sony tuner memory Lourens Analogue Source 8 18th July 2005 06:45 PM
NAD 7020, problem with tuner++ (centering). hanspd Solid State 0 26th January 2004 01:37 PM
DIY FM Tuner - what's the problem? jackinnj Solid State 3 26th April 2002 08:49 PM


New To Site? Need Help?

All times are GMT. The time now is 11:31 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2