[Elecraft] KPA500 (another view)

[Johnny Siu]

Hello Vic.
 
I agree with you that every dB does count in marginally situation.  Over 90% of hams in Hong Kong live in high rise multi-storey apartments.  Antenna on the roof is always not allowed by local regulations.  I am only using hamstick horizontally mounted on the window frame.  In this situation, I sold my ICPW-1 in exchange for a KPA500 because I have never had the chance to run the PW1 at full 1kw.
 
There are situations where improvement in antenna is nearly impossible.  Then a few more dB power is really necessary.  The official power output of KPA500 is 500 w but I find it can easily work at some 600w SSB without any difficulties.

TNX & 73,


Johnny VR2XMC


________________________________
 從︰ Vic K2VCO <k2vco.vic at gmail.com>
收件人︰ Elecraft Reflector <elecraft at mailman.qth.net> 
傳送日期︰ 2012年01月18日 (週三) 8:53 AM
主題︰ Re: [Elecraft] KPA500 (another view)
  
It isn't really a question of what's more important. Of course if you don't call on the 
right frequency you won't get through even with 5 kW. It's about what happens "other 
things being equal" in poor conditions, near the noise level or in a pileup.

On 1/17/2012 4:30 PM, Alan Bloom wrote:
> Very true.  But even 6 dB would not make a big difference for a
> rag-chewer or a casual contester.  Even for a fairly serious DXer, being
> in the right place at the right time and having superior operating
> skills are more important than an S-unit of signal strength.
>
> The place where the best possible signal is really essential is for a
> world-class contest station.  Those guys agonize over every fraction of
> a dB of feedline loss.
>
> Alan N1AL
>
>
> On Tue, 2012-01-17 at 16:20 -0800, Vic K2VCO wrote:
>> Keep in mind that it all adds up. If you get 2 db more from your beam, and 3 db from going
>> from 500 to 1000 watts (say), and maybe a db by replacing your old coax, etc., that's 6 db
>> -- a huge advantage.
>>
>> On 1/17/2012 4:15 PM, Alan Bloom wrote:
>>> Interesting experiment Dave.  I think that kind of test is valid for VHF
>>> operation.  But on HF it is very rare to hear a signal at a constant
>>> level like that.
>>>
>>> Normally signal strength varies considerably from moment to moment due
>>> to fading.  Even if the average signal level is right at the noise
>>> level, most of the time it will be well above or well below that level.
>>> A dB or two increase or decrease will vary the percentage of time the
>>> signal is copyable, but only a little.  The QRM also varies in signal
>>> strength from moment to moment.
>>>
>>> Of course, louder is always better.  But unless you are a big-gun
>>> contester, where winning or losing depends on a few extra contacts over
>>> the course of the weekend, I think you'd have a hard time noticing a
>>> couple dB difference in normal operation.
>>>
>>> I am just about to order a 2-element SteppIR Yagi.  I decided that the
>>> extra dB or two of the 3-element model is not worth another $450.  :=)
>>>
>>> Alan N1AL
>>>
>>>
>>> On Tue, 2012-01-17 at 16:52 -0700, David Gilbert wrote:
>>>> A power ratio of 3 (1500 watts versus 500 watts) is just under 5 db.
>>>> Check out these audio files (CW, though ... not SSB) I generated to see
>>>> what kind of impact that can have for readability of signals near the
>>>> noise threshold.
>>>>
>>>> http://www.ab7e.com/weak_signal/mdd.html
>>>>
>>>> 73,
>>>> Dave   AB7E
>>>>

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/

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