6500 Not Keying PTT on Elecraft KPA500 AMP

Reggie

After hooking up
my 6500 to the Elecraft KPA500 and KAT500, I am unable to get the 6500 to key the Amp.  I currently have the RCA TX1 from the 6500 connected to the KAT500, then the KAT500 PTT RLY connected to the KPA500 PA Key.    I have a coax cable on antenna 1 on the 6500, and it is connected to the RF Input on the KPA500.  Another coax able is connected to the KPA500 RF Out to the KAT500 XMTR.

 

 I also enabled the TX1 in SDR v1.6.21 Transmit settings, and disabled the ATU on the 6500.  When I press the tune button on the 6500, the KAT500 tunes and the frequency data changes to the corresponding band on the KPA500.  When I press the PTT on the mic and transmit, the 6500 transmits, but the amp is not keying. The RF power on the 6500 is set to 25 watts.  The amp is in OPER mode and indicates *PWR 0 on the display.  No power LEDs or SWR LEDs illuminate.  I am able to make contacts from the 6500 when I have the amp in standby mode.   By the way, I am not using DDUTIL att.

 

Any ideas as to what I am missing to configure with my setup?

Reggie

Ken - NM9P

Is there a profile setup on the kpa500 that needs to activate its PTT?

Jeff

Hi Reggie, Make sure you have the KPA 500 in operate mode and not standby. Jeff KD5RC

Reggie

The amp is in operate mode.

Reggie

Reggie

How do I setup a profile to activate the PTT to key the KPA500? 

Brian Morgan VK7RR

Reggie, some basic fault finding. First, check the lead from TX1 on your 6500 to see if it grounds on transmit (disconnected from your linear).

 With my linear I needed a relay in the TX1 line as it did not like the current being drawn by my THP linear PTT circuit. If it does ground, you are nearly there. Put a relay in the line so that the relay will close your PTT circuit. If no grounding on transmit, then your setup of your Flex is not correct.

Enabling TX1 in your transmit settings is a start but have you written that into a profile? If not, it will probably default to no transmit options being enabled. I have seen this happen many times until people write the transmit settings into a profile or all their profiles so TX1 is set for what you want.

In the Radio Setup Transmit menu pull up each profile that you want to write this to and TX1 should then be part of all those profiles.
Good luck. Brian.

Jeff

i have the same setup as you. Troubleshoot it by connecting the 6500 directly to the KPA 500 and the ptt line directly from the 6500 t0 the KPA 500. If it works you have something wrong with your cabling.

Reggie

Jeff,

Basically you want me to remove the KAT500 from the hookup?

Reggie 

Jeff

I suspect that the kat 500 may not be keying the KPA 500. I also use a buffer relay like Brian.

Jeff

In the radio setup box, transmit tab, I have rca tx 1 enabled with 0 time. I also have tx inhibit disabled.

Jeff

For your transmit profile go to the top menu left side, select profiles, profile manager, hf only. And select the load button.

Jeff

Yes

km9r.mike

I suspect this is the issue. This was not addressed in his set up description and seems to be semi important : ).   I wonder if it is discussed in the manual ? It appears page 105 is the key.

Tony C kc2dis

I use a relay buffer too..

Mark Erbaugh

Use the Elecraft KAT-500 utility program (from the Elecraft website) and make sure the KAT-500 does not inhibit amp TX

Walt - KZ1F

Mine worked and works right out of the box. I only have the RCA cable from the 6500 to the kpa500. Just follow the wiring instructions that come with the Elecraft.

Walt - KZ1F

I didn't do any of that, just turn on the RCA jack in the main radio setup under transmit. Do you have the kat500 in front of the kpa500? You want that after the amp.

Reggie

The KAT500 is in front of the KPA500. 

dlwarnberg

Reggie, did you get this resolved??   If not make sure you have the proper RCA jack enabled for TX...  go to settings, radio setup, Transmit tab... you will see there ACC TX, RCA TX1, RCA TX2 RCA TX3.. next to each should be a ZERO and a Enabled or Disabled button.. enable the one you have from your KPA500 to the RCA plug on the radio, then take a look at the "TX profile" listed there, you will notice if you do not save this setup the RCA TX port can disable when you change TX profiles, so you will want to save a TX profile to enable the amp...  I have the exact same setup

Good Luck

David

Walt - KZ1F

You want the antenna tuner between the amp and antenna.

Reggie

Walt,

I have it wired as shown on the attached drawing.  This drawing was in the KAT500 manual page 12.

Reggie

Reggie

David,

I did not have time to work on the amp yesterday, but the RCA TX1 is enabled in the settings, radio setup, Transmit tab, and it is listed in the Transmit Profile.

Reggie

Walt - KZ1F

That is not my page 12. My page 12 shows the Key Out, from the transceiver plugging into the PAKey on the KPA500. Look at the pg 12 in the KPA500 booklet. What you are referring to is page 12 in the KAT500 booklet and is predicated on the PTT relay which is unnecessary. I have the 6500 ptt line directly connected to the amp, not the ant tuner. It has worked fine since I first installed it over 2 yrs ago. Note also, in the KPA-500 manual it clearly states no key buffer is necessary. Reggie, seriously, I think you've over complicated this...and it doesn't work.

dlwarnberg

Did you build the KPA500 from the kit or did you have Elecraft build it? same question for the KAT500?

Reggie

Elecraft built it.

Reggie

Walt,

I rewired the cables so a RCA cable connects from the PA Key on the KPA500 to the Key Out (TX1) on the Flex 6500; however, I still cannot key the amp.  I removed the RCA cable which was connected to the Tuner. I verified the TX1 is enabled, and the amp is in OPER.

Reggie

dlwarnberg

Turn everything off, pull the RCA plug that goes from the radio (RCA TX1) to the amp, leave it plugged into the radio.  Turn the radio on, put an ohm meter across the plug and key the mic.. do you get a signal?

Arnie

Reggie:
The TX1, TX2 and TX3 RCA jacks are mis-labeled on some of the diagrams floating around. On my F6.5k, they are on the upper row of jacks, not the bottom row as shown in some diagrams provided by Elecraft. FYI, that is what solved the problem for me. Check it out.
73 de Arnie

Reggie

David,

I measure 23.5 ohms across the plus when I key the mic.

Reggie

dlwarnberg

Take that RCA plug and plug it into the PA Key port on the back of the KPA500.. be sure to set the FLEX output to less then 40 watts, I'd suggest testing with 20 watts to start (all depends on the band you are operating on) turn everything on and test..

also, from radio you should also have the antenna out to amp, then out of amp to tuner (KAT500), then to antenna of course..  with everything set correctly it should key the amp as well when you key the radio.

If it does not key the amp, is there a fault light lit on the Amp?
Also, check your HV in the amp.. push the menu/HV key. It should be between 65 and 85 volts, if not check to make sure you set the mains voltage and tap correctly in the amp.

http://www.elecraft.com/manual/E740150%20KPA500%20Owner's%20man%20%20Rev%20D2.pdf

Walt - KZ1F

Try this (and I am loathe to tel anyone 'try this"). Completely remove the KAT500. Test one thing at a time and dont re-add the tuner until the amp keys properly.