Yes Bob the manual says that, but that statement in the manual was not revised 
after the 4.9x firmware update.
If you look at the manual revisions, that wording has been in the manual since 
the problem was initially discovered and before the 4.9x firmware update.

73,
Mark, WB9CIF

-----Original Message-----
From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On 
Behalf Of Bob McGraw K4TAX
Sent: Tuesday, August 20, 2019 21:11
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] KPA500 Coax size requirements

Because in the manual, page 4, item 2 states "Connect to the station 11 to 15 
VDC power supply with the white striped lead to the positive terminal."

I view it best to always follow the manufactures instructions and not 
re-engineer the product or rewrite the manual.

73

Bob, K4TAX


On 8/20/2019 3:27 PM, Ken K6MR wrote:
> "The KAT500 can be {should be} powered from the radio 12V supply."
>
>
>
> Interested why this is true.  Can the KAT500 tell the difference between 
> Elecraft 12V and Generic 12V?  Seems odd.
>
>
>
> I ran two KAT500s on generic 12V from a DIN rail power supply for 5 years.  
> Necessary because the tuners and the amps were remoted in a closet 20 feet 
> from the operating desk.  No problems.
>
>
>
> Ken K6MR
>
>
>
>
>
> ________________________________
> From: elecraft-boun...@mailman.qth.net 
> <elecraft-boun...@mailman.qth.net> on behalf of Bob McGraw K4TAX 
> <rmcg...@blomand.net>
> Sent: Tuesday, August 20, 2019 12:59:11 PM
> To: elecraft@mailman.qth.net <elecraft@mailman.qth.net>
> Subject: Re: [Elecraft] KPA500 Coax size requirements
>
> Carter:
>
> The KAT500 can be {should be} powered from the radio 12V supply.   I
> don't suggest a separate wall wart.
>
> The KPA500 can be powered from either 120VAC or 240VAC, your choice.  
> It should drive on all bands with 20 to 30 watts output from the K2 to 
> reach full 500 watts output from the amp.
>
> As to coax, yes RG-8X is OK up to 30 MHz as long as the SWR is low.  
> The Belden Power rating is 1000 watts up to 10 MHz, 370 watts at 50 MHz.
> Loss is 0.9dB / 100 ft @ 10 MHz and 2.1 dB / 100 ft at 50 MHz.   These
> power ratings are matched conditions.
>
> What is the SWR on your wire loop on the feed line for all bands?   Per
> Belden, the UL voltage rating is 300 V RMS.  Thus 500 watts at 50 
> ohms, i.e. 1:1 SWR, is 158 volts.  However, 500 watts into 500 ohms, 
> i.e. 10:1 SWR, is 500 volts.  So to answer your question, YES and NO, 
> depending on SWR on the coax between the tuner output and the loop antenna 
> feed point.
>
> In general, R-8X is OK at 500 watts below 30 MHz.   From experience, it
> will get "warm" to the touch.  "Warm" is created by loss which is then 
> heat generated from RF.  And that is RF which is not getting to the 
> antenna.
>
> Personally I'd opt for a balanced open wire feed to the loop and a 
> very good 1:1 balun rated for legal limit or more at the KAT500 tuner output.
>
> 73
>
> Bob, K4TAX
>
>
> On 8/20/2019 2:11 PM, Carter Craigie wrote:
>> Hello friends,
>>
>> I am contemplating buying a KPA500 amplifier/tuner Combo, and driving 
>> it from my Elecraft K2/100 rig. I hope I would be able to do that!
>>
>>    From what I have read on eHam Reviews, it appears that I can run 
>> the amp/tuner combo on 117v. from the convenient wall socket. Is that 
>> correct, as well?
>>
>> I cannot find any mention of the coax requirements, from the 
>> radio/combo out to our 80-meter wire loop antenna. Right now, using 
>> only my K2/100 I am able to use  8X coax.
>>
>> Will I still be able to use that coax cable with up to 500 Watts output?
>>
>> What other considerations do I need to make?
>>
>> Thanks in advance,
>>
>> Carter Craigie, N3AO
>> Blacksburg, VA
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
>
> This list hosted by: http://www.qsl.net Please help support this email 
> list: http://www.qsl.net/donate.html Message delivered to 
> k...@outlook.com 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
>
> This list hosted by: http://www.qsl.net Please help support this email 
> list: http://www.qsl.net/donate.html Message delivered to 
> rmcg...@blomand.net
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message 
delivered to markmus...@outlook.com 
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com 

Reply via email to