Ameritron AL 572 set-up to Flex 6300 tuning problems

Hugo Escalante

I'm not able to get enough power output to tune the AS 572 tube amp.

On my FTDX3000 I set it to CW at 25 watts then key up and apply power till I get .6 on plate current, adjust Plate and Load then raise power again till about .6 to .7 on plate then adjust Plate and Load again looking for the dip per Ameritron instructions.

On the Flex 6300 I'm not able to reach only .4 on Plate and nothing else.

I'm connected from the back of Flex 6300 TX1 (enable) to back of amp relay.

Any help, just received my 6300 yesterday and WHAT A RADIO GREAT STUFF

BTW it works perfect with my ALS 600 Solid State but doesn't like the tube.

Simon Lewis

turn up the tune power with the slider - Tune PWR under the RF power slider top right

K9DUR

Simon is 100% correct.  I set the tune power to 50W to tune my AL-572.  You have to set it separately for each band, but once set, the tune power setting is remembered each time you start the radio.

73, Ray, K9DUR

Hugo Escalante

Guys it doesn't seem to matter what setting I place it at it seems it only go to .4 on the plate current once I get to 100 Watts. I am using the  Tune PWR under the RF power slider on the top right. Ray what mode are you setting the Flex when you tune it up? Works find on the ASL 600.

Steve (N9SKM)

silly question but you are using the Tune button to Xmit for tuneup right?

Hugo Escalante

yes

James Del Principe

Hugo, is it possible that the SWR into the AL572 amp is high?     Does this happen on all bands?   Do you have an SWR/pwr meter between the 6300 and the amp.   I have a 6500 and the AL572 amp but have a small SWR/Watt meter there just to be certain. You can also look at the SWR reading on the Flex.    73, Jim

Steve W6SDM

James, that's exactly what I was going to suggest.  Look at the SWR.  I assume the ALC is set up correctly if it's working with the other amp.

Hugo Escalante

I have the MFJ 998 tuner between SWR is Flat on the Mosely TA53

James Del Principe

You have an MFJ tuner between the 6300 and the AL572 amp?     That should NOT be necessary. The amp has a tuned input for each band and really does match well.     Please try without the tuner and see the results.    73, Jim

Steve (N9SKM)

I 2nd what James says. There is no reason for a swr/wattmeter or tuner to be there. The rig has onboard power and swr monitoring.

James Del Principe

Hugo, did you ever resolve this?   Since I have such a similar setup and mine works fine, I am curious to find out. I'm sure we would all like to help you.    Best 73, Jim