No, the ERP is doubled: same total power radiated * twice the gain (3dB) = twice the ERP. What happens is that the voltages received from each antenna add in phase (in the optimum direction) which ac
The double figure-8 is excellent for making rope eyes, either in bare rope or tied around a metal or nylon eye. I've used it a lot, and never had one slip, or even show signs of movement. Another goo
I'm using a small KR-600 rotator, and the torque isn't always as much as it needs to be because of the voltage drop along 150ft of cable. (It isn't a capacitor problem - been there, checked that.) Do
Almost all moonbounce operators are using satellite screw-jacks, because they are so much stronger and better value than sidewise conventional rotators. The readout methods vary a lot, depending part
A brick chimney will support a lightweight VHF/UHF antenna on a short mast, but beyond that you're living dangerously. When you bind together a block of brickwork using chimney lashings, the effect o
You wouldn't want to know the price of a genuine Andrew splice. It includes a double-ended self-tapping gadget to join the two inner conductors together, with fancy tapered self-cutting threads - one
Also, HF yagi booms are just the size for small birds to get inside and then get stuck. End caps prevent that (but there are other solutions as well). 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
In that price range, something like the KR-600RC is a reasonable buy. (After Yaesu took over Kenpro they changed the number, but IIRC it's still something with a 600 in it). The "RC" is the important
"Hairpins" bent from any old stiff wire. Swap you a big box of them, for your ticket to Dayton. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) http://www.if
Try an auto starter ring and drive gear: large diameter, hardened steel, and free from a scrapyard. Still, the original question was about turning a two-foot dish with a 1-2deg beamwidth. The issues
That's what most people find. With intensive modeling of both the yagi and the support structure, it is possible to get the gain degradation down to about 1dB - information from F/G8MBI (hosted at my
You can expect high-order VHF resonances in normal lengths of guy wire, considerable scattering causing pattern distortion, and some loss of gain. Obviously these effects will depend on the azimuth o
Not likely! Rules of thumb are just as bad as extreme cases. There is no substitute for thinking about the *actual* case. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for R
The last few editions of the ARRL Handbook have had it correct. Anyone who doesn't already have one of the big fat ones with a disk in the back would do well to update to the latest edition - there h
Remember that chimneys are not really designed or built to support anything other than themselves. The sideways wind force on the mast translates into a turning moment which tries to break the mortar
I have two 40ft military surplus air-operated Clark masts here. The section length is 6ft and the whole thing nests down to about 7ft which is very convenient to work on. The handbook says it can be
Corrosion between the dissimilar metals is always going to ruin those threads. Either you can't get the bolts out, or when you do, they take a layer of corroded internal thread out with them. Every t
Not sure - but whatever you do, make all the sets of radials identical. G3HCT wrote an article for RadCom last year which showed how important that can be in getting a really good F/B ratio in all sw
Rusting is a combination of oxidation and hydration, so it requires both an oxidizing environment and free water. When the cement paste cures by forming an interlocking crystal structure (which gives
A TV transmitter engineer told me about a length of RG213 that was being used as a UHF attenuator, so it was intentionally running quite hot in continuous broadcast service. Even then, it took 7 whol