I can tell you this there is a world of difference between 800w and 2.5k or even 1.5k for that matter. I am in 0 land and very hard to break the coasts on a good day at times so a little extra helps break those pile ups. Fred N0AZZ
Sent via the Samsung Galaxy S6 edge+, an AT&T 4G LTE smartphone-------- Original message --------From: ae...@carolinaheli.com Date: 09/18/2015 1:16 PM (GMT-06:00) To: 'Edward R Cole' <kl...@acsalaska.net>, Elecraft@mailman.qth.net Subject: Re: [Elecraft] Product Suggestion - 500W Dummy Load Forgive me in advance if this is a stupid question. Is there any reason you have to tune at full power? It seems to me that tuning can be accomplished easily with much lower power. The same thing goes for the ATU to the antenna. I don't see why we need more than a few MW at most for the ATU to Antenna link. Rightly or wrongly when I was in the hobby the first time I ran a TS-850 into an SB-220 to an MFJ roller tuner connected to an antenna switch feeding: 80m inverted V, 30m/40m rotatable dipoles, and a triband beam. Whenever I tuned on the inverted V or outer band limits of where my antennas where tuned I ended up putting labels on the ATU on cap position and a number/clock combo that represented a roller inductor position for each band area I cared about. It ended up I rarely had to tune up anything one the air because I knew where the antenna tuning was using just the Rig and ATU; tuned the APM into a paintcan MFJ load then switch it inline. I was all set and never had issues when I needed to kick in the horses. Now my debate is 500w vs 800w... there's a larger difference between 500w and 800w than between 800w and 2.5kw signal wise if I understand correctly... Jerry Moore AE4PB, K3S - S.N. 010324 -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Edward R Cole Sent: Friday, September 18, 2015 2:00 PM To: Elecraft@mailman.qth.net Subject: Re: [Elecraft] Product Suggestion - 500W Dummy Load Don't have much to say: Had a Cantenna from Heath in the 60's - knocked over; spilt mineral oil on the floor, threw can away! I have acquired "dry" loads over the years rated into UHF and sometimes to mw at flea markets and swaps. My highest power load is 500w Sierra with power meter and switch for 150 or 500w (probably good to 1000-MHz). Have a couple Bird terminations rated 50w. Most can handled double their rating for short duration. The hardest duty on my loads is when optimizing the output of a new unit where I'm keyed up longer than I should. But I do have a question on how adjusting a tuner into a 50-ohm load saves one from transmitting a signal once the tuner is connected to an antenna that may not be 50-ohms. On 600m my inverted-L is Z = 0.8 +j680. Tuning into a 50-ohm load does nothing to help match the antenna. The amplifier is solid state with input and output transformers (no adjustment). I think, unless you use a high power tetrode or triode, that no one tunes amplifiers anymore. Solid state amps are broadband and need LP filters to keep from amplifying harmonics. BTW my 2m-8877 is capable of 2000w* RF output so pretty hard to find a dummy load to take that. Fortunately the amp does not change much so very little tuning is ever needed (of course I am on a small segment of one band about 200-KHz wide). Of course the answer is to tune antenna at lower power and hope the High Power amp will always be looking at 50-ohms. I do not have a QRO 2m antenna tuner but the antenna SWR < 1.25 so only the anode tuning needs a light adjustment occasionally (loading has not be adjusted for 8 years). My "dummy load" has 19.2 dBd gain and radiates well. *I operate at 1365w CW which allows for about 9% variance in meter accuracy to stay legal. 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubus...@gmail.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 je...@carolinaheli.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 m...@totalhighspeed.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
