Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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

Technics FM Tuner switches from stereo to mono to beat of music!
Technics FM Tuner switches from stereo to mono to beat of music!
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 9th July 2017, 07:54 PM   #21
ssi is offline ssi  United Kingdom
diyAudio Member
 
Join Date: May 2017
Location: North West England
Happy with it! Not ground breaking sound but good for the garage and my electronics tinkering space. Using it with a Pure Highway for DAB (BBC 6 Music) which has a built in FM transmitter for use in cars and works great for the garage. My car has DAB so no longer use it. The Wharfedale Diamond III's are not too bad and fit on a small shelf. Using it with my JVC AX220 (35wpc - diamonds hard to drive) but may try it with a Technics SU800 (50 wpc) which I have in the loft. All this kit (not DAB!) has lasted this long (30 years) so should survive a UK garage (dry).
  Reply With Quote
Old 9th July 2017, 11:51 PM   #22
davidsrsb is offline davidsrsb  Malaysia
diyAudio Member
 
Join Date: Dec 2005
Location: Kuala Lumpur
T101/2 off tune causes the FM detector and mute circuits to do just what the OP reports. Mooly should really say never touch the front end. Adjusting the FM detector can be done with a simple multimeter.
  Reply With Quote
Old 10th July 2017, 06:27 AM   #23
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Technics FM Tuner switches from stereo to mono to beat of music!
Quote:
Originally Posted by davidsrsb View Post
Mooly should really say never touch the front end.
I thought I did

Quote:
Originally Posted by Mooly View Post
I would advise caution on altering any of the tuned circuits, once you do you will never be able to bring them back again without correct test equipment.
  Reply With Quote
Old 10th July 2017, 12:44 PM   #24
davidsrsb is offline davidsrsb  Malaysia
diyAudio Member
 
Join Date: Dec 2005
Location: Kuala Lumpur
The FM detector coil is the only exception, and that one only the primary coil should be touched. Adjusting the secondary coil requires a test generator and distortion analyser
  Reply With Quote
Old 10th July 2017, 01:53 PM   #25
DF96 is online now DF96  England
diyAudio Member
 
Join Date: May 2007
The term 'front end' means different things to different people. Some (including me) use it to mean the VHF part of the circuit. Others may use to mean everything up to and including the discriminator.
  Reply With Quote
Old 10th July 2017, 05:48 PM   #26
Osvaldo de Banfield is offline Osvaldo de Banfield  Argentina
diyAudio Member
 
Osvaldo de Banfield's Avatar
 
Join Date: Dec 2011
Location: Barrio Garay,Almirante Brown, Buenos Aires, Argentina
Front end usually refers to the part from aerial to first IF transformer coupling, like in old TV sets.
__________________
Osvaldo F. Zappacosta. Electronic Engineer UTN FRA from 2001.
Argentine Ham Radio LW1DSE since 1987.
  Reply With Quote
Old 17th May 2019, 07:25 PM   #27
ssi is offline ssi  United Kingdom
diyAudio Member
 
Join Date: May 2017
Location: North West England
Default Did this and fixed it - finally got round to it!

Quote:
Originally Posted by ej25awd View Post
None of these, it's T101 for centre tuning. Use TP101 and TP102 for checking the center alignment. Tune to strong station, use a digital voltmeter. The polarity does not matter when measuring TP101 and TP102, all you care about is adjust T101 until you get as close as possible to zero volts between the 2 test points.

Check the AC ripple across C708 100uF/35V, it should only be about 10mV or less. It is possible that C713 100uF/35 that is part of the voltage doubler is dried up. C713 can be increased safely to 470uF/35. This capacitor has a hard life due to the amount of AC voltage across it. Increasing the capacitance will make it last longer.

Replace C705, C706 and C707 too.

Don't even think of installing boutique capacitors into this tuner, it is not worth it.
  Reply With Quote
Old 17th May 2019, 07:30 PM   #28
ssi is offline ssi  United Kingdom
diyAudio Member
 
Join Date: May 2017
Location: North West England
Thanks ej25awd
  Reply With Quote
Old 19th May 2019, 02:09 PM   #29
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
Quote:
Originally Posted by Osvaldo de Banfield View Post
Front end usually refers to the part from aerial to first IF transformer coupling, like in old TV sets.
Front end is upto the first mixer usually. The front end is the only part of a receiver that has to be tunable.
  Reply With Quote
Old 19th May 2019, 06:21 PM   #30
ssi is offline ssi  United Kingdom
diyAudio Member
 
Join Date: May 2017
Location: North West England
Since changing the power supply related caps the display seems a lot sharper and brighter.
  Reply With Quote

Reply


Technics FM Tuner switches from stereo to mono to beat of music!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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Technics SA-300: dead FM tuner? Secret Chimp Solid State 25 1st June 2016 01:53 AM
Stereo FM tuner module Berget Analogue Source 4 28th October 2015 08:10 AM
Technics SA-300: dead FM tuner Chickenwatt Solid State 30 19th March 2014 05:19 PM
Output stage for a Mono FM tube tuner oldglide Tubes / Valves 7 7th March 2012 08:49 PM
The latest FM tuner Shootout review is up: Technics ST-8080 3moons Analogue Source 0 7th June 2004 04:37 AM


New To Site? Need Help?

All times are GMT. The time now is 09:53 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki