Flex 6600M keying Henry 3K Premier amplifier.

Steve KD2OM

Simple question, how do I key the Henry amplifier safely? The amplifier keys by a ground closure. It has +26 volts on the key line.

73,

Steve KD2OM

Jim K4JAF

Good luck on this one.. As I remember from some years ago, the Henry used a large open pole relay with no suppressor diode across the coil thus one heavy back surge when keying.. My best to your radio keying circuit.. Jim K4JAF

K5XH

Hi Steve,

I have keyed a Henry 2K and a SB200 amp with my 5000 and 6600. I built a little circuit in a small box to go between the Flex and the amp. It was just a junkbox 12V relay and a couple other parts. The relay contacts connect to the amp. I believe I used a couple of transistors and a couple resistors. Probably an easier way but I used what I had.

A friend keys his older amp with one of these: https://www.dxengineering.com/parts/ame-arb-704

Hope this helps!

73, Mark K5XH

Steve KD2OM

Thanks Mark,

I found a solution that I already had but forgot about. I have a Denkovi USB relay board that the 6600M recognizes. I just configured one of the relays to key the amplifier.

I looked into the ARB-704, that probably would have been the next step.

73,

Steve KD2OM

HalM

Harbach Electronics sells a small Keying Interface circuit board that protects sensitive HF radios from
high-voltage Keying energy in older Heathkit amplifiers.
https://harbachelectronics.com/