Cable radiation, anyone? I've yet to see a review of a CFA/EH that demonstrated the reviewer understood that possibility, took serious precautions against it, and then measured it. Lacking all that,
Don't worry - INSIDE the station, you are not expecting large lightning currents in the RF ground bonding, so the grounding bolts on the backs of the rigs are already quite big enough. The purpose of
While not disagreeing with the facts that Eric states, I do think it's putting a possible problem ahead of the main Big Idea of lightning protection. The Big Idea is to create a protected environment
Good point. As our stations grow larger and more complex, the 'star' grounding method becomes less and less realistic. You wind up with connections of very different lengths running back to the grou
This is one of those old approximate concepts which gives a useful general understanding, but it is no substitute for modern modeling techniques. For a general discussion, see: http://www.ifwtech.co.
If Bob (who started this thread) buys the ARRL Antenna Handbook to get a copy of HFTA, he'll find that author N6BV approaches the whole problem in a radically different way. Instead of jumping straig
[...] Extending HFTA to vertical polarization has to be top of everybody's wish list... but the whole problem is much more affected by ground conductivity and permittivity a long way out from our ant
A slightly frivolous reply to a very serious question... The Royal Navy's way of dealing with the risks around remotely operated gun mountings is to post a helpful warning notice. I found this messag
You'll find some information in my 'VHF/UHF Long Yagi Workshop' pages, including a link to an online calculator. 73 from Ian GM3SEK www.ifwtech.co.uk/g3sek ___________________________________________
There were many VHF long yagi designs developed from the 1940s through the 60s and 70s, but all the amateur designs were based on range measurements with large margins of error. The famous NBS design
That is categorically not true. Computer modeling has revolutionized antenna design, so we're using much stronger magic now. (Let's not take the Harry Potter line of argument any further... but I'm m
Don't worry - you just happen to have chosen a slightly tricky antenna for your first outing. Roy Lewallen hangs out on the rec.radio.antenna newsgroup, and he also responds to direct e-mails... but
Think about buying an SDS impact drill: http://www.diyfaq.org.uk/powertools/sds.htm These tools are now in the DIY price range, and the difference from your old hammer drill is amazing. Even a small
Ground rods are quite easily stopped by small rocks, but don't give up on the SDS yet. You can buy drill bits up to 1.0 metre long, which do a surprisingly good job of either breaking up the rocks or
No, the extra ionisation was too localised to make any dramatic difference. What they did find was radioactively contaminated rainwater running down lightning conductors... and if one of the radioact
"Or both"... interesting idea - has anybody here used it? On a smaller scale - five posts for verticals, rather than a tower - I'll soon have 20 of these anchors to put in, so would welcome any and a
Thanks for all the replies - and I hope Les is getting as much useful information from my replies as I'm getting from his. I already had your site bookmarked, Joe. That must be the largest dental cro
Sorry - I should have said "adhesive anchors". Unfortunately my backyard is like that too - a random mix of large and small boulders, everything from granite to slate-like shale, all brought here by
The Spiderbeam is another wire/fibreglass beam that was designed for DXpeditions and has a good track record: www.spiderbeam.net -- 73 from Ian GM3SEK _______________________________________________
Any triangle system can be used with either two or three elements energized - check with ON4UN's book for details. In either case, the most practical and versatile system for beam switching is the eq