[Elecraft] KPA500/KAT500 and RTTY

[Dave Cole]

Thank you Richard.

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources

On 12/2/20 3:50 PM, DC wrote:
> I run 500 watts FT8 6 through 80 meters with a maximum SWR of 1.2 to 1 into an 80 meter full wave loop and a 6 meter beam.  Even on the hottest of days I have never seen 70 degrees on the KPA500 utility.  BTW, I use it 95% remote and it works great.
> 
> If I ever saw over 70 degrees I would let it cool down and look for a problem.   The utility is great for remote operation with a program like team viewer or Google Remote.
> 
> Richard
> K6VV
> 
> 
> Sent from my iPhone
> 
>> On Dec 2, 2020, at 3:02 PM, Dave Cole <dave at nk7z.net> wrote:
>>
>> Thank you Bob, getting some actual numbers helps...  I cut off operations at 70C.  In fact, if it starts getting above 65, I will terminate ASAP.  Knowing it could get to 90C makes me feel a lot better!
>>
>> 73, and thanks,
>> Dave (NK7Z)
>> https://www.nk7z.net
>> ARRL Volunteer Examiner
>> ARRL Technical Specialist, RFI
>> ARRL Asst. Director, NW Division, Technical Resources
>>
>>> On 12/2/20 1:25 PM, Bob McGraw K4TAX wrote:
>>> While I don't often run RTTY, I do run a good bit of PSK-31, WSJT-X FT-8 and MSK-144 along with CW and SSB modes.   I do watch the PA temp, specially as it nears 65 to 70 degrees C.   I also run with the Fan on #1 or #2 for starters.    I know some will say it doesn't make a difference while others say it will.   As to me, I know that heat is the downfall of solid state electronics.  Cool is always better.
>>> For the above, I normally run 400 to 500 watts, depending which power indicator I choose.  And, a very important point,  at any time I never exceed 500 watts into a well matched load.   I do have a Bird 43P with a 500 watt, 2 - 30 MHz, element in-line between the amp output and ATU input.   I also have a 500 watt element, 25 - 60 MHz, for 6 meters.
>>> Two facts to which I view one must pay attention:  {per the KPA500 manual}
>>> (a) Duty Cycle a 500 watts = 10 minutes key down / 5 minutes standby
>>> (b) Heat Sink Temp = 90°C Maximum  {194° F}
>>> I view if one exceeds either of these two items above........they just became a very underpaid design and test engineer.
>>> 73
>>> Bob, K4TAX
>>> Message: 1
>>> Date: Wed, 2 Dec 2020 08:36:54 -0800
>>> From: Dave Cole<dave at nk7z.net>
>>> To:elecraft at mailman.qth.net
>>> Subject: Re: [Elecraft] KPA500/KAT500 and RTTY
>>> Thanks sir...
>>> 73, and thanks,
>>> Dave (NK7Z)
>>> https://www.nk7z.net
>>> ARRL Volunteer Examiner
>>> ARRL Technical Specialist, RFI
>>> ARRL Asst. Director, NW Division, Technical Resources
>>>> On 12/2/20 8:24 AM, Gordon LaPoint wrote:
>>>> Dave,
>>>>
>>>> I have done many RTTY contests and regular qso's using the
>>>> KPA500/KAT500/K3 over the last few years. I run full 500 watts with no
>>>> problems, the temp gets up to the 60 to 65 range a lot when calling CQ
>>>> in a contest, or during a 10 minute tx.? If the temp gets to 70 then the
>>>> fan kicks into high gear and is very noisy, but still within specs.
>>>> Gordon - N1MGO
>>>>
>>>>> On 12/2/2020 9:57 AM, Dave Cole wrote:
>>>>> Hi,
>>>>>
>>>>> Any recommendations as to the max power I might run using a KPA500 and
>>>>> KAT500, on say, a three to five minute transmission?
>>>>>
>>>>> Also, what is the recommended max temp for the PA on this device as
>>>>> measured by the KPA500?
>>>>>
>>>> _
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft at 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 dave at nk7z.net
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at 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 vetterestorer at gmail.com