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Re: hi power mobile
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Harold Mandel
¿ªÔÆÌåÓýOn the Bechtel/AWS project just before, during and after the WTC disaster we serviced cell site antennae throughout Manhattan as well as all the other boroughs. ? When going out on the roof of WTC1 it was necessary to wear a grounded RF suit with internal EME detector calibrated for alarms at less than 50 uW-to-alarm. ? The stupidest work picture I ever saw were these two geniuses climbing on the Empire State Building broadcast array in the middle of the day without hard hats, without safety glasses, without gloves. The picture was taken from above, so there was a third genius on the array. The photo was distributed by the ES&H people at Bechtel. ? Hal W4HBM ? From:
ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of Robert B. Bonner ? There is very little tissue heating at HF. -----Original Message-----
From: ham_amplifiers@ On Behalf Of badgerscreek Sent: Wednesday, January 10, 2007 5:34 AM To: ham_amplifiers@ Subject: [ham_amplifiers] Re:hi power mobile I think those Yellow Top Batteries are called Optima Batteries? I dont know why nobody is concerned about having their brains so close to the antenna? I mean sitting in the near field of the antenna running 1 or more kilowatts at the higher frequencies would have me worried. Maybe the adrenalin rush is more potent than worrying about your health, or maybe theres no danger? Greg --- In ham_amplifiers@ > > --- In ham_amplifiers@ > wrote: > > > > --- In ham_amplifiers@ > > > wrote: > > > > > > It's kind of funny watching the thread about the mobile > amplifiers > > and > > > voltage requirements. > > > > ##### I have zero experience with it. I was just waiting for > you > > to come out of the wood work.... since I knew you guys had this > down > > pat... and was all old news. The deep cycle communications > > batteries work pretty good. > > > Right now, they're running those yellow top batteries with the spiral > cells. They claim these to be the best. Also, there's really no limit > to the batteries that you parallel together to get the power required > you need. The more batteries, the longer you can run. I've seen the > big 24V batteries used in diesel rigs too ran in these set ups. The > ones you want have the largest amp-hour ratings. > > > > > > ### I also read in an old QST... where they would use 2 x > > batteries in series.... like those used in golf carts..... but one > > was 6 V... and the other was 8 V. [didn't even know u could get > > deep cycle batteries... big ones... in 6 + 8 V ] Then ur car > > regulator would charge em to 14 .3 V..... then with engine OFF.... > > ur small 706-mk-2-G would last way longer. That setup was also > > used in some Field day event's. > > > > > > > > > > > They use a charging system consisting of a 24 volt alternator, > and > > run > > > parallel / series combos of standard car batteries (or standard > > and deep > > > cycle, if they are smart) to have a 24 volt electric system. > One > > > alternator, and a pair of batteries will power quite a large > > system, as > > > > ### Don't some of em use train alternator's ??? Think they > > were split stator, dual rotor.... or split rotor, dual stator... > > made by Neville Leece.... at 1000 A per stator ?? Or was this > > for the tube setups ?? > > > They'll use like 6 of the Leece Neville alternators under the hood to > power the big solid state amps. Some have used generators that can > provide 115/230 Vac too ran off the belt. > > > > > > ### I still haven't seen any detailed website on this hi power > > mobile stuff. Trying to generate the power is a huge project in > > itself. RFI, etc... Rf decks... is another issue. You are > > right... hams are just trying to reinvent the wheel. > > > Right, not a lot has been published on this as it was all done sort > of under the table away from the FCC. > > > > > > Later... Jim VE7RF > > > > > > > --Toll_Free > > > > > > > > Best, > > Will > Yahoo! Groups Links
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