6500 Not Keying PTT on Elecraft KPA500 AMP

Norm - W7CK

WARNING:  I'd highly recommend installing DDUtil and making sure you have it set up to automatically reduce the output power of the Flex to 18w or so when the amp is in OPERATE mode.  I have no affiliation with the product but have nothing but praise for it.

All you need to do is accidentally key up with 100w on cw into your amp and you can kiss it goodby.  I know because I've had it happen to me.  I know, the KPA500 is suppose to be fool proof, but I can attest to the fact it will damage the PA immediately....  I don't know WHY Flex sets the power output default to 100 watts, but they do.   All you need is a hiccup in the software and not notice that the PO has defaulted to 100w and without DDUtil keeping a watchful eye, you can say goodby to your amp.  Oops.....

I'm sure I'm not the only one this has happened to....

George KF2T

Maybe a silly question, but does the amp go into TX when you ground the remote PTT jack on the KPA?

Brian Morgan VK7RR

(Hi to my old friend George!)

 In relation to setting power levels, I fully endorse Norm's comments about DDTUil. There is an additional way to limit power out, using your Profiles and going to your Radio Setup menu, Transmit submenu and on the left hand bottom column you can adjust your output power to whatever level you want. In my case on 2 metres I need 50 watts to drive my linear, so I adjusted the power level until it read 50 watts, stored that in my 2 metre Profile and I no longer have to worry about power levels. Profiles are a very powerful tool! You will know it is working as your RF Power slider will not allow you to go beyond the level you have set.

Reggie

I got the amp to key.  Thanks for all the help.  My friend swapped the input / output coax cables on the amp and my mic gain was too low on the 6500.  I tested the amp on 40 meters and I am getting 420 watts out with 25 watts drive.  Now, I will set up DDUTIL. 

Reggie

Reggie

Norm,

Will DDUTIL work with the Maestro?

Reggie

Norm - W7CK

Yes it does.  I have it loaded on my primary workstation and have been using my Maestro from all over the house today.  The problem is that the Maestro does not let me switch my amp from STBY to OPER.  I actually have to go into the office and press the button on the KPA500.  When I do that and place it into OPER, DDUtil automatically reduces power output of the Flex to 18 watts which is what I have it set at in DDUtil.

It is much better from a laptop because It provides full control of the Flex, amp and tuner from the laptop.  The laptop also runs SmartSDR and provides all 8 panadapters, 8 slices, logging program and digital modes and access to the internet all in a small package.

I'll keep playing with the Maestro though.

dlwarnberg

you can also limit max power output in the radio setup, transmit tab... so when setting up an amp it's wise to set your max drive power..

73's

Reggie

Brian,

Which version of SDR are you using because I do not see the option to adjust the output power on the Radio Setup menu, Transmit submenu?

Reggie

dlwarnberg

1.7.30.. but I believe it was there in previous versions as well..

Radio Setup -> Transit tab -> bottom of screen lowest box.. says "Max Power" by default it's set to 100

Brian Morgan VK7RR

1.7.30 Reggie and the description of where it is by Dave is where I was suggesting you look.

Reggie

I found it.  Thank you.

Reggie

I found it. Thank you.

dlwarnberg

Reggie,  if you use DDUTIL you can set max drive power there for each band and do not need to set it in SmartSDR.. in DDUTIL - setup - AutoDrive.

Good luck

David