Elecraft

KPA500/KAT500 and RTTY

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Bob McGraw - K4TAX

KPA500/KAT500 and RTTY

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<[hidden email]>
To:[hidden email]
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?
>>
> _

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NK7Z

Re: KPA500/KAT500 and RTTY

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<[hidden email]>
> To:[hidden email]
> 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:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

DC-3

Re: KPA500/KAT500 and RTTY

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 <[hidden email]> 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<[hidden email]>
>> To:[hidden email]
>> 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:[hidden email]
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

NK7Z

Re: KPA500/KAT500 and RTTY

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 <[hidden email]> 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<[hidden email]>
>>> To:[hidden email]
>>> 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:[hidden email]
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to [hidden email]
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]