[Amps] Fwd: Re: Modern rig amplifier keying

Bob Wilson, N6TV n6tv at arrl.net
Sun Jul 21 15:27:57 EDT 2019


Congratulations on getting this to work, but like most other modern radios,
the TS-590SG has an option to enable an internal mechanical relay to key
amplifiers that required more than 10ma.  Unfortunately, it is poorly

See footnote 2 on page 55:

*2 Mechanical Relay Operation.  You can switch the signal of the high
voltage like a vacuum tube linear amplifier.  It is possible to control the
terminal voltage of TL-922 (approximately -140 V).

First set both Linear Amp menus No. 59 (HF) and 60 (VHF) to Option 3 to
enable the TS-590SG mechanical relay.  Also rewire the amplifier's KEY IN
to TS-590SG REMOTE Connector Pin 4 (MKE) instead of to Pin 7 (RL), which is
only used for silent solid-state keying of more modern amplifiers that
require low current.  REMOTE Pin 2 is ground / shield.  See diagram on Page

The KEY OUT connector of an Elecraft K3/K3S (RCA) can key up to 200VDC at
5A (with no noisy relay).  It also has a KEYOUT-LP pin on the ACC connector
rated at only 10ma max, for more modern amps.  No menu changes needed
except TX DLY.

Bob, N6TV

On Sun, Jul 21, 2019 at 7:45 AM Stan Gammons <s_gammons at charter.net> wrote:

> Someone ask what amp and rig. The amp is a Clipperton-L I converted to a
> pair of GI-7BT tubes. Relay is 12 volts and draws around 100 ma when the
> coil is energized.  I haven't decided on a rig, but was considering a
> TS-590SG. I see 10 milliamps is all the TS-590SG will switch. So, I
> decided to re-engineer a Harbach SK-401 I had left over after installing
> a ES4L4-B in my L-4B.  Around 15 volts was the minimum voltage the
> SK-401 would operate at, so I swapped R1 and R2, 22k 1/4 w resistors,
> with 18K 1/4 watt resistors and the circuit will now operate with 12
> volts, possibly lower though I didn't try it. I measured .788 milliamps
> to trigger the SK-401, so I think it will be fine to use with the
> TS-590SG or possibly any other modern rig. The youngest rig I have is a
> Omni VI.
> Thanks again for all of the replies.
> 73
> Stan
> On 7/20/2019 9:34 AM, Glen Zook wrote:
> > Having 12-volts on the keying circuit (actually, usually, 13.8-volts)
> > is very common and I don't know of any "modern" transceiver that
> > cannot handle the voltage.
> >
> > Glen, K9STH
> >
> > Website: https://k9sth.net
> >
> >
> > On Saturday, July 20, 2019, 08:32:43 AM CDT, Stan Gammons
> > <s_gammons at charter.net> wrote:
> >
> >
> > How much voltage will modern rigs tolerate on the keying circuit? I have
> > an older amp that has a 12 volt relay. Will that fry the keying circuit
> > of a modern rig?
> >
> >
> > 73
> >
> > Stan
> > KM4HQE

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