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 <[email protected]> 收件人︰ Elecraft Reflector <[email protected]> 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/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
