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 > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Closed Thread
 
Thread Tools
Old 25th Jul 2022, 11:27 pm   #1
netsmo62
Tetrode
 
Join Date: Nov 2020
Location: Nonantola (MO), Italy
Posts: 56
Default Kenwood R-5000 LSB reception defect (and IF SHIFT don't work)

Hello, from some time I have this Kenwood R-5000, complete with optional filters, which has a defect that I have already seen dealt with on this forum years ago on this post https://www.vintage-radio.net/forum/...d.php?t=135051, the inability to properly demodulate the LSB (except with the wide filter were voices are hearable) that result like voice pass through a very tight filter. In the post guy talk about having tested the frequency of the PLLs with respect to the type of modulation, but I honestly did not understand where these frequencies would have been found ... anyway, I have already recalibrated the 4 PLLs (they were all lower in voltage than the requested value) as described at page 70 of service manual but to no avail. In addition, it seems that even the IF SHIFT command does not work, turning the potentiometer does not feel any change in reception. I also proceeded both to clean the electronic components from dust and to go over all the ground contacts under the fixing screws. I have tried to check BFO frequency on the R139 wire with a digital counter as service manual claim, but perhaps I have wrong something, I don't find any fq on this point...any help will be appreciated, thank you F.

Last edited by Radio Wrangler; 26th Jul 2022 at 7:37 am. Reason: ebay reference removed
netsmo62 is offline  
Old 23rd Oct 2022, 7:37 am   #2
netsmo62
Tetrode
 
Join Date: Nov 2020
Location: Nonantola (MO), Italy
Posts: 56
Default Re: Kenwood R-5000 LSB reception defect (and IF SHIFT don't work)

Hello, I am writing this message as a "self-response" to the problem I had with this Kenwood R-5000 now that I have managed to fix it myself, for others who may be in the same situation as me.

I had contacted the guy who had the same problem in the past and asked for help on the forum, but without getting great explanations as to how he had finally fixed his Kenwood except a laconic "I had it recalibrated and then it was okay".

So I re-read his post carefully and focused on the fact that the defect only appeared after he had disassembled and reassembled the front. And there the light bulb came on "Do you want to see that some connectors on the receiver boards has moved and no longer makes contact well?".

So I also disassembled the front and checking the front board in fact there was a connector slightly raised on one side and I pushed it back inside. In the meantime, I also discovered why the volume control malfunctioned and jammed at one third of the travel: the rear Bakelite bottom of the double potentiometer was probably deformed due to a frontal impact of the receiver almost certainly due to a fall on the ground. And for the same reason, the connector is certainly raised to one side on the front board.

I easily fixed the volume control by lightly squeezing the four metal ears of the control body and placing a drop of acrylic glue on the crack that had formed in the bakelite. After the reassembly, tested the radio, everything is OK! Even the LSB was now working correctly !! As for the alleged non-functioning of the IF SHIFT, in reality there was no defect, only that I did not remember that the command does not work in AM, but only in SSB Thanks for your attention, regards F.
netsmo62 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 5:59 am.


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.