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Electronic Video Blog / Re: 84 Christmas in the shop and a few updates
« Last post by Radio Tech on Today at 09:01:30 PM »
Quote from: Gene on Today at 08:45:41 PM
Hi my name is Gene and I have lots of tantalum caps. I have some 6.7 mf ones if that would help you. let me know  gdebevic @gmail.com

Hi Gene and welcome.
I did purchase a few of those but they go fast.

Thanks for stopping in.
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Electronic Video Blog / Re: 84 Christmas in the shop and a few updates
« Last post by Gene on Today at 08:45:41 PM »
Hi my name is Gene and I have lots of tantalum caps. I have some 6.7 mf ones if that would help you. let me know  gdebevic @gmail.com
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Ham Radio Circuits and Repair / Re: Kenwood TS-140s strange receive audio issue has me confuzzled.
« Last post by Radio Tech on October 18, 2017, 07:39:57 PM »
Those are nice rigs. But so full of bad solder pads.  I take it you now have a rig working correctly?
Also look around those regulators on the top board. They are really bad for solder cracks.
Good job tracking that down.
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New member welcome / Re: New Member Bob - KQ2Q Northeast GA
« Last post by Radio Tech on October 18, 2017, 07:37:01 PM »
Welcome Bob. Sorry so late in the reply. Really busy these days. Appreciate you sharing your story with us. Will be looking forward to your post. Sounds like we really have a lot in common.


Thanks Bob and snowbird for the kind words.
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Ham Radio Circuits and Repair / Re: Kenwood TS-140s strange receive audio issue has me confuzzled.
« Last post by km4gig on October 13, 2017, 10:05:12 PM »
Lookie what I found on the signal trace going into K6. Hmmmm interesting .....
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New member welcome / Re: New Member Bob - KQ2Q Northeast GA
« Last post by Bob KQ2Q on October 13, 2017, 08:31:43 AM »
Thanks Snow Bird!
Yeah - for Sure.
Buddy has the Experience and the Knowledge
And the Tenacity to Find the Problem.
Thanks again.
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New member welcome / Re: New Member Bob - KQ2Q Northeast GA
« Last post by Snow Bird on October 12, 2017, 11:00:06 AM »
Welcome  Bob!  Hop you enjoy the Site.   Buddy is a good Freind to have if you get lost in the wiring he can help you out
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Ham Radio Circuits and Repair / Re: Yaesu FT-101 - Hoping to fix.
« Last post by Bob KQ2Q on October 12, 2017, 08:51:30 AM »
Hello Mael,

I read your Posts and would suggest that you locate a Manual and Schematic with Transistor Audio Output.
Let me know if you have a better schematic with a non-IC audio circuit.
If not, I will try to find something like that for you to use.

If there is no schematic, then I should be able to find a typical 2 transistor output, audio amp schematic. Most audio amps in the 3 to 5 watt range are reasonably similar.

We can then look at the DC Supply voltages at the Audio Amp.

My first thought is that the large capacitor between the Collector(s) and the Speaker is leaking. That will cause oscillation and squeal.

Keep me posted. I will assist where I can.
A picture of your audio amp board would help also

-Bob KQ2Q  Danielsville, GA
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New member welcome / New Member Bob - KQ2Q Northeast GA
« Last post by Bob KQ2Q on October 12, 2017, 07:51:45 AM »
Hello All,

I have been enjoying Buddy's Video's on YT for the last week. We have so much in common - it seems.
Located near Athens, GA and licensed for 49 years with continuous Building and Repairing over the years.
I also enjoy RC Airplanes and Gliders - 45 years. I play Guitar and Pedal Steel for too many years to mention :)

I am currently just about to Retire from Work (a bit overdue) and start working on the Boat Anchor PILE!
A Clegg Interceptor Receiver is first in line.... yeah; its got the big Jackson Brothers Dial - Analog - Of course!

I hope to be a regular here; and Help and Enjoy my time on the Forum.

I would like to add a Service Monitor to my Bench. Something that I have always wanted and needed. But; I have gotten by without so far.

Best Wishes to All here!

-Bob KQ2Q   Danielsville, GA   ::) 8)
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Ham Radio Circuits and Repair / Kenwood TS-140s strange receive audio issue has me confuzzled.
« Last post by km4gig on October 11, 2017, 11:59:47 PM »
I have an issue in my Kenwood TS-140s that has me a bit puzzled. Whenever I tune to anything between 4.000Mhz and 7.499Mhz, the radio has very low audio. The weird thing is that if I tap the PTT or turn the send/recieve switch on/off, the audio comes up and usually stays up until I go to another band and come back.
Tonight I started digging and believe I've narrowed it down to something funky with the signal path through K5 and K6 on the filter board. The notation on the schematic indicates that these relays switch on the frequency range of my problem.
Voltages at the source (IC1 on the signal board), connectors, and relays are all good and match voltages measured on the other relays. But i know that does not necessarily mean the relays are latching.
Something else that I noticed is that when I touch any of the even numbered relays (output side) including K16, the audio sometimes changes either up or down but this does not happen on the odd numbered (antenna side) relays. Also lightly touching the board with my finger in random places will change the audio.  All of this only happens when tuned between 4.000 and 7.499.
I'm thinking about pulling the board and swapping K5 and K6 with K7 and K8 (one at a time) and see if the problem follows the relay(s). If it does, I'll order the relay(s), but if not, what else should I check? Or is there something els I should check before trying a relay swap?
Filter unit schematic is attached for reference.
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