I built a replacement position indicator for my ProSisTel PST-71D rotator after the 10-turn potentiometer failed and I was to lazy to bring the rotator down from the tower to replace it. The solutio
I would bet a lot of money that those gas discharge tubes (which sell for all of 70 cents in unit quantities) would be more dependable than a ball gap. But yes, a drain choke would bleed off DC volt
A few weeks ago I described a system to remotely monitor the direction my antennas were pointing after the potentiometer in my Prosistel PST-71D crapped out. It used 18 discrete Hall Effect switches
Hi, Jon. I have a PST-71D rotator and I feed the motor with about 250 feet of solid #14 UF cable (the gray residential cable rated for underground use) from a 24 VDC power supply running through an i
The picture at this link shows severely corroded hollow tower legs that didn't just buckle ... there are multiple jagged breaks. https://dxnews.com/forum/forum/silent-keys/52187-dl6rai-bernard-buettn
Did you see the picture? The tower itself, not the mast, broke in multiple places roughly where one set of guys attached to the tower. You can even see the jagged edges of the hollow tower legs. Th
sigh ... Did you see the picture? The tower itself, not the mast, broke in multiple places roughly where one set of guys attached to the tower. You can even see the jagged edges of the hollow tower
Pretty sure it will also make short work of the zinc. Dave AB7E Steve NR4M Sent from my iPhone AlexTry a wire brush, then touch up any damage to the galvanizing with cold galvanizing compound. Rust
Only for those who don't understand the theory well enough to account for all of the possible variables. Admittedly that includes most of us, but this old attitude that theory can't be trusted is jus
Downward sloping Beverages will have a lower takeoff angle than upward sloping ones (assuming no high terrain in the foreground), but ANY Beverage benefits from the pattern discriminating against noi
I've never seen any reference to a mold like that, and somewhere I have an old list of all the molds Cadweld made. If you get desperate, though, you could try making your own. http://www.ab7e.com/e
It might be possible to modify those 5/8" ceramic molds (maybe by using a grinder bit in a Dremel) to handle a 3/4" rod and three #2 wires, but I doubt it would work very well. Not enough room left
I've used magnesium ribbons before as well, but the sparklers work much better ... at least for me. I've also considered making more of the flash powder to use as starter material since the normal f
Twisting isn't the issue ... bending is. Look at it this way. Instead of yagis on the mast, picture blocks of equal weight strapped to the same side of the mast. To extrapolate for illustration, pi
If the screw broke off and is still in the hole, just choose a position nearby ... drill a new hole ... and tap it for threads for whatever screw you want to use. You can buy drill bits and taps tha
We've been talking inferior UHF connectors here (especially angle ones) and it doesn't require voltage breakdown ... current alone can do it. Assuming a KW on a 50 ohm line, a resistance of 0.1 ohm w
Hi, Joe. Detuning a tower and shunt feeding a tower seem to be essentially the same mechanism except for whether there is a feed or not, and I've often wondered why running a wire down the center of
There is a pretty good reason why there are multiple ... separate ... ham radio forums, including one dedicated to amplifiers. Dave AB7E On 2/5/2024 2:04 PM, n1bkb-- via TowerTalk wrote: No, Al, it
Good luck finding a 200 foot self supporting tower. Does he have any idea at all what that would look like? Dave AB7E On 2/28/2024 11:15 AM, RVZ via TowerTalk wrote: A ham friend in Illinois in look
I have played around with HFTA using terrain files that I manually generated by simply editing an existing file to create cliffs and sharp ridges. It's very easy to do and comes up with interesting