[Elecraft] [K2] Driving a Kenwood TL-120 AMP

[Don Wilhelm]

David,

You can easily check to see if the amp keying is compatible with the K2 
keying interface - all you will need is a DMM.

Power the amplifier and measure the open circuit voltage at the "PTT" or 
"KEYING" input.  If that voltage is positive and not higher than the 
breakdown voltage of the K2 keying mod output device, then so far, so good.
If all was good for that last test, proceed with the test, but if it was 
not good, you will need an interface of some sort (relay or other).
Now set your DMM to measure current and place one probe on one side of 
the PTT input to the amp and the other probe to ground (or the other 
side of the PTT input).  Expect the amp to key, so protect it with a 
dummy load.   Your meter will tell you how much current is required to 
key the amp.  If that current exceeds the current rating for the K2 
keying mod output transistor, you will need an interface, but if it is 
within the current rating, then connect them directly.

73,
Don W3FPR


davidvk2nu at virginbroadband.com.au wrote:
> Hi All,
>
> I'm in the process of aquiring a old kenwood TL-120 100w amp, which I plan
> to drive with my K2. 
>
> Just wondering if anyone has any details of doing this, before I try and
> figure things out for myself. My K2 is modded with a external keying
> output, and I'm wondering whether I can use this to key the TL-120
> directly, or whether an additional interface will be required.
>
> Cheers
>
> David, VK2NU
>   
>