[Elecraft] TL-922

[Joe Subich, W4TV]

The TL-922 does not have snubber diodes across it 100V relays.
The back EMF spike will kill the KeyOut circuit in the K3.

*ALWAYS* use a key line buffer with a TL-922 that has not
been fitted with a soft key circuit.

73,

    ... Joe, W4TV

On 3/29/2023 8:25 AM, Mark Musick wrote:
> Per the K3 manual page 17 the K3 can key +200VDC @ 5A.
> No need to have a key line buffer if the amp keying voltage and current meet those specs.
> 
> 73,
> Mark, WB9CIF
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of James F. Boehner, MD via Elecraft
> Sent: Wednesday, March 29, 2023 11:55
> To: 'Josep Torres' <ea6bf at aol.com>; 'Elecraft Reflector' <elecraft at mailman.qth.net>
> Subject: Re: [Elecraft] TL-922
> 
> Josep,
> 
> Be sure to install a soft-key interface in the TL-922 before hooking it up to the K3.
> 
> https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fharbachelectronics.com%2Fshop%2Fkenwood-tl-922%2Fsk-922-soft-key-keying-interface%2F&data=05%7C01%7C%7C3477a90435fe4f56f8db08db304cb2c8%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638156878191285160%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CtTlkUMq2f5c%2B0nckmeEK0YKKnhuYA1WQzNFfEbCFbo%3D&reserved=0
> 
> The newer rigs were not meant to handle the voltages on the older amplifier's keying circuits.
> 
> I modified mine with the soft-key board and added the new capacitor block.
> 
> '73 de JIM N2ZZ
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of Josep Torres via Elecraft
> Sent: Wednesday, March 29, 2023 3:03 AM
> To: Elecraft Reflector <elecraft at mailman.qth.net>
> Subject: [Elecraft] TL-922
> 
> Hi guys,
> 
> Have a couple of Kenwood TL-922's around and was thinking to connect one to a K3.
> Has anybody done so.? And if so, how have you done the wiring.?
> Got 2 K3's (in fact I have 3 of 'em, but one not physically at now now) and maybe one day I can use the spare one with a TL-922 from another QTH.
> 
> Thanks,
> 
> 
> 73,
> 
> Josep
> EA6BF
> BUG #256  -  CWops #3072  -  FOC #2182 (ex 1724)
>