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Re: TS-870S no TX

 

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P.S.....
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Should read "...control line connectors."

----- Original Message -----
Sent: Thursday, March 13, 2025 7:55 AM
Subject: Re: [Kenwood-Amateur-Radio] TS-870S no TX

All I can suggest is that you tighten all the screws fixing the board to the chassis, then pull and then reseat the dc and control like connectors...It could simply be an oxidized interconnection contact. If it's a cold solder joint, that might require a little more work to determine.?Intermittents can be a PITA...I use a Philips head screw driver. Use one that fits snugly with no play...
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73...Jordan VE6ZT
----- Original Message -----
Sent: Thursday, March 13, 2025 7:25 AM
Subject: Re: [Kenwood-Amateur-Radio] TS-870S no TX

Well this is frustrating ...
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I removed the screen cover from the Final unit to access the TX/RX relay and now it's working again ?.
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I couldn't see anything loose so I'm in the dark as to what's causing it.
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Maybe I just put it back together and see if it fails again.
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Incidentally what is the correct type of screwdriver for this radio? Posidriv, Philips or something else? I don't want to damage the pristine screws.
?
--
Mike G8GYW


Re: TS-870S no TX

 

?
All I can suggest is that you tighten all the screws fixing the board to the chassis, then pull and then reseat the dc and control like connectors...It could simply be an oxidized interconnection contact. If it's a cold solder joint, that might require a little more work to determine.?Intermittents can be a PITA...I use a Philips head screw driver. Use one that fits snugly with no play...
?
73...Jordan VE6ZT

----- Original Message -----
Sent: Thursday, March 13, 2025 7:25 AM
Subject: Re: [Kenwood-Amateur-Radio] TS-870S no TX

Well this is frustrating ...
?
I removed the screen cover from the Final unit to access the TX/RX relay and now it's working again ?.
?
I couldn't see anything loose so I'm in the dark as to what's causing it.
?
Maybe I just put it back together and see if it fails again.
?
Incidentally what is the correct type of screwdriver for this radio? Posidriv, Philips or something else? I don't want to damage the pristine screws.
?
--
Mike G8GYW


Re: TS-870S no TX

 

Well this is frustrating ...
?
I removed the screen cover from the Final unit to access the TX/RX relay and now it's working again ?.
?
I couldn't see anything loose so I'm in the dark as to what's causing it.
?
Maybe I just put it back together and see if it fails again.
?
Incidentally what is the correct type of screwdriver for this radio? Posidriv, Philips or something else? I don't want to damage the pristine screws.
?
--
Mike G8GYW


Re: TS-870S no TX

 

Sorry - I now see you are asking about the 870s, not 570S.?


Re: TS-870S no TX

 

Mike,
([A=B] + POWER ON) should be a full reset, so you should be good there.
In your image what am I looking at (discolorization on the RF shielding); is that a burn mark?
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Random thoughts // questions:
1). Do you have an undervoltage situation (unit needs a bit more current to xmit, than rcv).? Maybe your PS is in need of a rest...
I'd carry the radio out to the car and see if I could get it into xmit into some dummy load at low power.
2). Or maybe your antenna feedline has a short.
3). Have you the right antenna selected?
4). I'd try removing and replacing the battery, then doing another FULL reset. I had read some posts in other places about this fixing similar problems.
5). Make sure all connectors (particularly the tiny coax ones are connected to their boards firmly).
6). Rx/Tx relay?
?
This is a pretty interesting and informative video on troubleshooting the TS-570:
?
Sam.


Re: TS-870S no TX

 

On Thu, Mar 13, 2025 at 12:44 PM, Jordan wrote:
What is that scorched discolored area...?? Looks like something arced or burned...
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Jordan...
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That's a reflection in the screening can ?.
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--
Mike G8GYW


Re: TS-870S no TX

 

Thanks Jordan, yes that was helpful.
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I found a good quality set of schematics on mods.dk and have identified the TX/RX relay which is switched by a TXB line.
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Time to start probing ...
--
Mike G8GYW


Re: TS-870S no TX

 

?
What is that scorched discolored area...?? Looks like something arced or burned...
?
Jordan...

----- Original Message -----
Sent: Thursday, March 13, 2025 6:15 AM
Subject: Re: [Kenwood-Amateur-Radio] TS-870S no TX

Manuals sometimes show a partial reset and a full or complete reset.
Bob W4JFA

On Wed, Mar 12, 2025 at 2:54?PM Mike via <mail=[email protected]> wrote:
On Wed, Mar 12, 2025 at 04:39 PM, Bob wrote:
If you haven't already, try a factory full reset. I'm not a professional tech but I've fixed 2 radios in the past year and a half doing a full reset.
Bob W4JFA
Thanks Bob. I tried the Full Reset described in the instruction manual ([A=B] + POWER ON) to no effect.
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Is that the same as the factory reset?
?
The Mic socket and ACC2 are wired to the TX-RX Unit X57-4620-00. Unfortunately the schematic in my downloaded copy of the service manual is very fuzzy. Is there a better one somewhere?
?
--
Mike G8GYW


Re: TS-870S no TX

 

Manuals sometimes show a partial reset and a full or complete reset.
Bob W4JFA

On Wed, Mar 12, 2025 at 2:54?PM Mike via <mail=[email protected]> wrote:
On Wed, Mar 12, 2025 at 04:39 PM, Bob wrote:
If you haven't already, try a factory full reset. I'm not a professional tech but I've fixed 2 radios in the past year and a half doing a full reset.
Bob W4JFA
Thanks Bob. I tried the Full Reset described in the instruction manual ([A=B] + POWER ON) to no effect.
?
Is that the same as the factory reset?
?
The Mic socket and ACC2 are wired to the TX-RX Unit X57-4620-00. Unfortunately the schematic in my downloaded copy of the service manual is very fuzzy. Is there a better one somewhere?
?
--
Mike G8GYW


Re: TS-870S no TX

 

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Get the service manual and read the portion that deals with the RX/TX change-over. I'm pretty sure you'll find a description as to how the change-over is implemented. Normally there are voltages such as RXB and TXB or similar, which are switched on the transition.
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Clearly that process is not working since RX doesn't turn off when you try to transmit...That's likely your first clue...
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I hope this helps....73...Jordan VE6ZT

----- Original Message -----
Sent: Wednesday, March 12, 2025 9:51 AM
Subject: Re: [Kenwood-Amateur-Radio] TS-870S no TX

On Wed, Mar 12, 2025 at 03:12 PM, David Frechette wrote:
You should be able to find a schematic and trace the circuit, at least in theory!
I have the schematic, just hoping for some pointers. Nothing happens when I operate PTT, it stays in RX.
?
--
Mike G8GYW


Re: TS-870S no TX

 

On Wed, Mar 12, 2025 at 04:39 PM, Bob wrote:
If you haven't already, try a factory full reset. I'm not a professional tech but I've fixed 2 radios in the past year and a half doing a full reset.
Bob W4JFA
Thanks Bob. I tried the Full Reset described in the instruction manual ([A=B] + POWER ON) to no effect.
?
Is that the same as the factory reset?
?
The Mic socket and ACC2 are wired to the TX-RX Unit X57-4620-00. Unfortunately the schematic in my downloaded copy of the service manual is very fuzzy. Is there a better one somewhere?
?
--
Mike G8GYW


Re: TS-870S no TX

 

If you haven't already, try a factory full reset. I'm not a professional tech but I've fixed 2 radios in the past year and a half doing a full reset.
Bob W4JFA?

On Wed, Mar 12, 2025, 11:51 AM Mike via <mail=[email protected]> wrote:
On Wed, Mar 12, 2025 at 03:12 PM, David Frechette wrote:
You should be able to find a schematic and trace the circuit, at least in theory!
I have the schematic, just hoping for some pointers. Nothing happens when I operate PTT, it stays in RX.
?
--
Mike G8GYW


Re: TS-870S no TX

 

On Wed, Mar 12, 2025 at 03:12 PM, David Frechette wrote:
You should be able to find a schematic and trace the circuit, at least in theory!
I have the schematic, just hoping for some pointers. Nothing happens when I operate PTT, it stays in RX.
?
--
Mike G8GYW


Re: TS-870S no TX

 

You should be able to find a schematic and trace the circuit, at least in theory!


Re: TS-870S no TX

 

On Wed, Mar 12, 2025 at 12:34 PM, David Frechette wrote:
Possible that the ALC board DC-DC converter has quit. I had that happen to my TS850; all the lights but no TX. Just my guess.
Thank you David. My plan is to (hopefully) gather some suggestions before opening it up.
?
--
Mike G8GYW


Re: TS-870S no TX

 

Possible that the ALC board DC-DC converter has quit. I had that happen to my TS850; all the lights but no TX. Just my guess.


TS-870S no TX

 

Hi everyone
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I bought this radio from a dealer a year ago. It is in immaculate condition despite its age and worked flawlessly until now.
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It would start to drop out of TX occasionally during a QSO and I initially suspected my PTT switch.
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Now it won't transmit at all. I have tried PTT on the front panel mic connector, the rear ACC2 socket, the SEND button and AT TUNE.
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Any ideas where I should start looking for the fault?
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Mike G8GYW


FS: NIB Kenwood CW filter for TS520 and others

 

Now here is a rare find. I have for sale a Kenwood 500hz CW filter, listed as the YF-3395C-1 but it looks identical to the more common YG3395C. ?This fits the 520, 599, 511, 510, and other radios with a 3.395mhz IF. ?It is brand new! ?I opened up the box and it still have the foam padding around it which has pretty much disintegrated. ?Has the original box and instruction sheet with it
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I am asking $50 shipped in the US and can take paypal/check/MO.
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73 John AF5CC ?


Re: Kenwood SM-230 Station Monitor

 

I recently acquired a Kenwood SM-230 with original box and am excited to integrate it into my shack. I will take some unboxing photographs if anyone is interested.
73,
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David, WU3J


Re: TS680s Knob

 

Gary anyone who has a 3D printer can download all kinds of files from places like 'thingyverse', here are just a few of the knob designs available on there. Our club could make them because we have 3D printer, the cost of the filament is next to nothing, time on the printer is sendary to the time to make the design in a CAD type program, and but the cost to mail would make it prohibitive for a single knob. If you can find someone locally who has a printer, it would take minutes to print. It is also possible that one of the designs that are alredy avaiable could be modified. We have made knobs for older radios, and of course you can makes them in whatever color you fancy, but one of the grey filaments seems to be very close to the grey's used by many manufacturers.
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Jeff - NZ2S