The inner surface of the shield is on the job for the single unbalanced coax run, replaced by the second center conductor for the balanced case. So there is some difference in ohmic loss but wouldn't
Congrats, your second test message worked. You're in my email filter now! Pete KS4XG -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative re
This is the second time in a few days that we've seen the old chestnut about an S unit being six Db. It isn't, 99% of the time, it varies from rig to rig, usually varies across the range of the rig's
I'll stand by everything I wrote. If Yeasu got religion and arranged for the MP's S units to be 6db each, that's great but it puts that rig into a very select group. Based on all I've seen, the stat
130 pounds. The limit on the hinge is 3600 foot pounds of torque, so the configurations with shorter "tops" allow more weight. Question: When rebuilding a foldover I went with grade 5 bolts for the h
Bob writes about K3KO's measurement of a TS450 S meter: In the QST review the 450's S meter is reported to read S1 for 1.7uv of signal and S9 for 31uv. If that's 48db I'll eat my harness. Regards, Pe
Hi, When I crank my foldover up, if I don't restrain it with a rope it "falls" the last few degrees until it's vertical, slapping the tower with the boom. This is nonhabit forming :-) I adjusted the
The QST review of the TS450 measured S1=1.7uv, S9=31uv. Reviewing the basic math chapter of the Handbook: db = 20 log (E1/E0) and where impedance is constant, the power difference is: db = 10 log (E1
Hello Darrel, I'm copying the reflector about our discussion of wire size for wire antennas, where I raised the issue of skin effect with you. It wasn't the overheating leading to mechanical failure
(LB's explanation omitted) Notice that I didn't mention how much efficiency we'd lose with #18 wire vs #12 wire. This is because I couldn't figure it out! Thanks for the reminder about varying curren
Hi Jim, I suggest you try Dean Straw's "TL" program included with the ARRL handbook the past couple of years. There is an older version at the ARRL download site. This is a great tool for calculating
Hi LB, I'm preparing to assemble a Gem Quad right now. After completing many modeling runs with EZNEC and straight NEC2 I've abandoned the manufacturer's specs and am going with a switchbox and 1/4wl
Hi gang, Darrel AK6I pointed out foulups in my recent mail about RF resistance. I was in a hurry and misread the wire sizes in Sams "Reference Data for Radio Engineers" (sixth edition). Here's a tabl
I'm homebrewing a means of keeping kids safe from my just completed foldover and would like to bounce my schemes off the reflector to see if there is a better way. What I plan to do is take three str
Thanks to all for suggestions about a better anti-climb design. One elegant idea that came behind the scenes from KK1L uses 2x4s stuck on top of the panels to prevent them being lifted. The simple "s
If I use a pair of coax runs to create a balanced line of 2X impedance, should I care if moisture gets into the jacket? Would it create extra loss as it does with coax used in the usual fashion? Coul
I'm exploring alternative feeding schemes for a two element Gem Quad. After a ton of modeling I'm convinced the factory setup results in tradeoffs I can avoid. Actually, I'll be using the Gem Quad sp
Thanks for the input. The only ceramic feedthrough sources mentioned apart from Amidon are Davis RF (too large) and Surplus Sales of Nebraska (size unknown). Model airplane suppliers sell special "fu
Hi Folks, The thimbles I got from Texas Towers and Hill Radio come down to a narrow gap, too small for the thimble to slip over a turnbuckle or shackle. I need a practical idea for increasing the gap
Thanks very much for all the suggestions. Some were close enough to instantaneous to be astonishing. Two things. I should have said I was looking for a way to spread the thimble without knocking the