Hi Roger - The feedline from the dipole center back to the relay box, in my opinion, needs to "float". The dipoles that are not being driven depend on the reactance from the open feedline to lower th
P.S. With my feed systam I don't worry about exact matching and tune the 450 ohm line in the station with an old Johnson Matchbox. Gene / W2LU If you want a real eye opener the next time ____________
Nothing the matter with 5/8 wave verticals in a 4-square, but you would probably want to model it to get everything right. One of the guys down in New England had an 80 meter 4-square with 90 foot el
Agreed, HFTA is the way to go. ARRL Antenna Handbook ed 21 includes the software and instrustrutions you will need. A little hand held GPS will give you your tower location, and a fair bit of determi
Optimum height for a tower is a classic case of "it all depends". What are your interests?, What's the geography like at your QTH?, Are there obstructions?, Are there zoning restrictions? , What's th
As I recall wind pressure "on a flat surface" at 70 mph is 20.6 lbs/sq ft., so if the tower is rated for 18 sq ft at 70 mph, would it be too much of a stretch to say to the zoning board that since wi
Bottom line, if the manufacturer can't, or won't, give you 90 mph data or at least the projected tower area and, taking into account the materials used, the maximum allowable restraining moment, then
Hi Tony - Can you find out what's in the balun? Possibly a capacitor that is changing value as it heats up. Gene / W2LU _______________________________________________ _______________________________
Also, as I have mentioned off line to Tony, some fixed capacitors will drift consirderably with temperature changes often caused by circulating current in tuned / matching circuits. Possibly a compen
We have some commercial towers in the area of the final approach to one of the runways here in Rochester. As I heard one pilot say "run into one of those guys on a foggy night and you could ruin the
On a calm day, you could hang a string, with a small weight on the end, from the top of each tower leg. Gene / W2LU _______________________________________________ ___________________________________
As most of us know, there's almost always at least a little breeze at 100 feet , however Steve's problem with a crankup is only with 20 feet. Gene / W2LU -- Original Message -- From: "K8RI" <K8RI-on-
Hi Ted - You might check out Bernz-O-Matic, if they still make them. I've had one for many years. Nothing too elegant but it works. Gene / W2LU -- _______________________________________________ ____
Hi Roger - Regarding the 160m quarterwave slopers. Granted there may only be a few db F/B ratio with a qws but wouldn't you rather radiate 3KW than 1.5KW if it was just for the price of a bit of wire
Regarding "dipoles" there are a number of points that have been well presented: 1. If the antenna is to be used for multiple bands, keep it nonresonant to avoid feed point impedance extremes. 2. Shor
Hi Steve - You 've made a good point , however: an 80m dipole at 30 feet isn't going to be 1:1 on 50 ohm line and, how does it look off resonance out towards the band edges ? Gene / W2LU ____________
Hi SteveYes, but.... There are so many variables The best answer all depends............. switching to open wire and a tuner then adds the question of tuner efficiency which is quite variable and som
Hi Doug - Your twin towers sounded a bit familiar. Digging back in my "swamp" I came up with a two page "Collins "Product Description and Application" from the mid 1960's which describes their Model