KPA500 "bypassed" when off?


Ken WR7D
 

I have a new to me KPA500/KAT500 combo to go along with my K3S. I understand the standby and operate modes of the amp and the different power levels for each that the K3S can use. My question is will the KPA500 be bypassed when it is off and still use the KAT500 and the "standby" power setting on the K3S? I couldn't find anything in the manuals that mentioned this specifically. I did find one post that seems to indicate this, but it wasn't absolutely clear.


Tom Doligalski W4KX
 

Yes

 

On Jul 18, 2021, at 11:12 AM, Ken Simmons <flymustangs@...> wrote:

I have a new to me KPA500/KAT500 combo to go along with my K3S. I understand the standby and operate modes of the amp and the different power levels for each that the K3S can use. My question is will the KPA500 be bypassed when it is off and still use the KAT500 and the "standby" power setting on the K3S? I couldn't find anything in the manuals that mentioned this specifically. I did find one post that seems to indicate this, but it wasn't absolutely clear.


Ken WR7D
 

Thanks. I was going to ask this question also, but forgot. It doesn't look like the K3S will display the power level from the KPA500 like the KXPA100 and KX3 combo does. Is that correct?

Ken
WR7D


K9MA
 

That is true. The K3(S) will display its own output power. Unlike the KXPA100, of course, the KPA(1)500 has it's own display.

73,
Scott K9MA



On 7/18/2021 10:56 AM, Ken Simmons wrote:
Thanks. I was going to ask this question also, but forgot. It doesn't look like the K3S will display the power level from the KPA500 like the KXPA100 and KX3 combo does. Is that correct?

Ken
WR7D


-- 
Scott  K9MA

k9ma@...


Michael Kopec
 

Reminder, the KAT500 need about 20w or little more for a good tune. de K8NS

On Sunday, July 18, 2021, 12:08:22 PM EDT, K9MA <k9ma@...> wrote:


That is true. The K3(S) will display its own output power. Unlike the KXPA100, of course, the KPA(1)500 has it's own display.

73,
Scott K9MA



On 7/18/2021 10:56 AM, Ken Simmons wrote:
Thanks. I was going to ask this question also, but forgot. It doesn't look like the K3S will display the power level from the KPA500 like the KXPA100 and KX3 combo does. Is that correct?

Ken
WR7D


-- Scott  K9MAk9ma@...


Ken WR7D
 

Thanks. I was thinking about this from a remote control standpoint. I guess I can just make a table of K3S readings to KPA500 readings for remote ops. Unless there is a different way to accomplish this that I haven’t discovered.

 

Ken

WR7D

 

 

 

 

That is true. The K3(S) will display its own output power. Unlike the KXPA100, of course, the KPA(1)500 has it's own display.

 

73,

Scott K9MA

 

 

 

 


Ken WR7D
 

Thanks. I thought the KAT500 manual said 7 watts. Is 20 watts a more practical, field tested power? I know the short document that talks about integrating the K3S/KPA500/KAT500 says to set the K3S to 25 watts when training the KAT500. I guess it doesn’t really matter in my case. If I want to go below 20 watts, I would probably just use the KX3.

 

Ken

WR7D

 

 

 

 

 

Reminder, the KAT500 need about 20w or little more for a good tune. de K8NS

On Sunday, July 18, 2021, 12:08:22 PM EDT, K9MA <k9ma@...> wrote:

 

 

That is true. The K3(S) will display its own output power. Unlike the KXPA100, of course, the KPA(1)500 has it's own display.

 

73,

Scott K9MA

 

 

 

On 7/18/2021 10:56 AM, Ken Simmons wrote:

Thanks. I was going to ask this question also, but forgot. It doesn't look like the K3S will display the power level from the KPA500 like the KXPA100 and KX3 combo does. Is that correct?

Ken
WR7D

 

-- Scott  K9MAk9ma@...

_._,_._,_

 


Lyn Norstad
 

I find that the KAT500 tunes reliable at about 8 watts, although there may be a slight variance between bands.

 

But it does seem to tune faster with slightly more power.  I’d say maybe 1/3 less time to tune with 20 watts.  So if you’re going thru the whole training process, then yes – it makes sense to use a bit more power.

 

73

Lyn, W0LEN

 

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of Ken WR7D
Sent: Sunday, July 18, 2021 1:20 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] KPA500 "bypassed" when off?

 

Thanks. I thought the KAT500 manual said 7 watts. Is 20 watts a more practical, field tested power? I know the short document that talks about integrating the K3S/KPA500/KAT500 says to set the K3S to 25 watts when training the KAT500. I guess it doesn’t really matter in my case. If I want to go below 20 watts, I would probably just use the KX3.

 

Ken

 


Brian K0DTJ
 

I would think it would be better to tune above 12 watts and use the KPA3 rather than tuning at lower power and subjecting the LPA to high SWR during the tune cycle. 

73,
Brian, K0DTJ

On Jul 18, 2021, at 12:41, Lyn Norstad <Lyn@...> wrote:



I find that the KAT500 tunes reliable at about 8 watts, although there may be a slight variance between bands.

 

But it does seem to tune faster with slightly more power.  I’d say maybe 1/3 less time to tune with 20 watts.  So if you’re going thru the whole training process, then yes – it makes sense to use a bit more power.

 

73

Lyn, W0LEN

 

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of Ken WR7D
Sent: Sunday, July 18, 2021 1:20 PM
To: Elecraft-K3@groups.io
Subject: Re: [Elecraft-K3] KPA500 "bypassed" when off?

 

Thanks. I thought the KAT500 manual said 7 watts. Is 20 watts a more practical, field tested power? I know the short document that talks about integrating the K3S/KPA500/KAT500 says to set the K3S to 25 watts when training the KAT500. I guess it doesn’t really matter in my case. If I want to go below 20 watts, I would probably just use the KX3.

 

Ken

 


ab2tc
 

Hi,

I agree. I have set my K3S (and the spare K3) tuning power to 30W. This ensures that the final 100W amp (KPA3) will handle the tuning power working at the low end of its rating. It will probably *not* fold back power when encountering the high SWR encountered when the KAT500 is hunting for a solution. Power foldbacks are certain to confuse the tuner algorithm.

I also wish for a future Elecraft tuner that will actually *measure* the complex impedance of the load, calculate the components required for the "L" network to match it and switch them in in a single attempt. No more hunting. MFJ once claimed for one of its tuners to do exactly that. I once had one of those tuners and decided this was a false claim as the schematic clearly showed the impossibility of actually measuring complex impedance. It hunted crazily as they all do.

Knut - AB2TC

On Sun, Jul 18, 2021 at 06:31 PM, Brian K0DTJ wrote:
I would think it would be better to tune above 12 watts and use the KPA3 rather than tuning at lower power and subjecting the LPA to high SWR during the tune cycle. 
 
73,
Brian, K0DTJ

<snip> 


Bob McGraw - K4TAX
 

The KAT500 manual, page 2 states: "For better matching accuracy, tune with >20W."    This is more than 20 watts.  I consider that to imply equal to or more than, although the symbol > is actually more than. 

I have my K3S TUNE power set to 20 watts.  Why?  Because I use 20 watts for the KAT500 to tune.  It is also easier on the relays when running through the matching routine.   Then when my KPA500 is in operate mode if I hit TUNE the 20 watts will drive the KPA500 to rated output.  Thus there is NO risk of overdriving the KPA500 in TUNE mode. 

73
Bob, K4TAX


KE1F Lou
 

Would you say that the 20 watts also true when using it on FT8 mode.? FT modes seem to over shoot and my KPA500 was damaged such way.

73, Lou KE1F

On 7/19/2021 20:00, Bob McGraw - K4TAX wrote:
The KAT500 manual, page 2 states: "For better matching accuracy, tune with >20W."    This is more than 20 watts.  I consider that to imply equal to or more than, although the symbol > is actually more than. 

I have my K3S TUNE power set to 20 watts.  Why?  Because I use 20 watts for the KAT500 to tune.  It is also easier on the relays when running through the matching routine.   Then when my KPA500 is in operate mode if I hit TUNE the 20 watts will drive the KPA500 to rated output.  Thus there is NO risk of overdriving the KPA500 in TUNE mode. 

73
Bob, K4TAX


Rick NK7I
 

Later updates in firmware changed the value of 20 watts, to 10 watts.  It may not have migrated into the current manual.

I've used the 10 watt setting for years with the KAT500 and the KPA1500 and it's been tuning fine at that level.

Even safer for your conditions (except on 60M, which I've set up in case I have a stupid moment and flip on the amp/s).

73,
Rick NK7I

On 7/19/2021 1:00 PM, Bob McGraw - K4TAX wrote:
The KAT500 manual, page 2 states: "For better matching accuracy, tune with >20W."    This is more than 20 watts.  I consider that to imply equal to or more than, although the symbol > is actually more than. 

I have my K3S TUNE power set to 20 watts.  Why?  Because I use 20 watts for the KAT500 to tune.  It is also easier on the relays when running through the matching routine.   Then when my KPA500 is in operate mode if I hit TUNE the 20 watts will drive the KPA500 to rated output.  Thus there is NO risk of overdriving the KPA500 in TUNE mode. 

73
Bob, K4TAX


Jim Brown
 

On 7/19/2021 1:28 PM, KE1F Lou wrote:
FT modes seem to over shoot and my KPA500 was damaged such way.
Are you feeding audio to the rig from the Line Input, using DATA A, setting audio drive level per the manual for 4 bars of AGC flashing 5, and controlling KPA500 power by setting power out from the K3?

73, Jim K9YC


KE8G
 

Ken - WR7D,
You really don't need a chart to figure it out.  Elecraft has software that you can turn the KPA500 on/off and monitor output/SWR/temperature and any faults that might appear.  When I need a little extra power, chasing DX, I can fire up the KPA500 and know exactly what is going on.    Check out their website


73 de Jim - KE8G

On Sun, Jul 18, 2021 at 1:13 PM Ken WR7D <flymustangs@...> wrote:

Thanks. I was thinking about this from a remote control standpoint. I guess I can just make a table of K3S readings to KPA500 readings for remote ops. Unless there is a different way to accomplish this that I haven’t discovered.

 

Ken

WR7D

 

 

 

 

That is true. The K3(S) will display its own output power. Unlike the KXPA100, of course, the KPA(1)500 has it's own display.

 

73,

Scott K9MA