I just discovered the IN3OTD website which is a nice complement the other RF design websites familiar to topband station builders. Detailed performance measurements of various transformers commonly u
Hi Chuck, I have both a full size transmitting 4-square and a W8JI BSEF 8-circle array using 25 foot low impedance passive umbrella verticals. There are no active electronics in the W8JI's BSEF 8-cir
To add to Dennis' comments: you can never have too many antennas (very important exception: unless they interfere with each other). Very large arrays such as 8 circle arrays form their deep nulls in
Hi Jerry, There's a good chance the problem originates inyour control box rather than your rotator. Does the problem stop if you completely disconnect the control box? 73 Frank W3LPL -- Original Mess
Hi Trevor, Please share with us the details of your antenna and ground system Better transmit performance should be achievable 73 Frank W3LPL Running 1kw to a 55ft top loaded vertical over a decent r
Hi Trevor, I looked at your QRZ.COM page and I'm concerned that your tower and Yagis may be degrading the performance of your nearby 160 meter vertical. It can contribute unwanted nulls and unwanted
Hi Larry, A 500 foot Beverage will provide excellent results. Ground rods are only one solution. Excellent alternatives are chicken wire laid on the ground or multiple radials laid on the ground or b
Hi Gurt, With only two radials on your inverted-L, you should use a good common mode choke on your coax. The W2DU style choke on only one meter of RG-393 will not be very effective Suggest you read t
A reversible Beverage or BOG can be constructed out of a single run of RG-6, there's no need to form an open wire line out of two runs of RG-6, See ON4UN's Low Band DXing, Volume 5, page 7-88 and fig
Hi David, It should be perfectly okay to bury a short coaxial cable under the driveway with a matching transformer at each end that connects to each Beverage segment. Keep the coax as short as possib
I measured the difference in loss (dB per 100 ft) between solid copper (SC) center conductor RG-6 vs. copper clad steel (CCS) Quad-Core RG-6 coaxial cable. The difference is insignificant on 160 mete
Hi Rys, Simply change the turns ratios of the reflection transformer and matching transformer to correspond to the approximate termination impedance and feed impedance. 4:1 transformers work well for
Hi Rys, The terminationresistance of a BOG (including the loss in the ground rod and/or radials) is typically about 250 ohms. The value is non-critical, especially in the case of a BOG where most of
A senior FCC executive is now actively "on the case" 73 Frank W3LPL -- Original Message -- FWIW, the FCC has a 24/7/365 emergency contact number: 202-418-1122 _________________ Topband Reflector Arch
Hi Martin, Matching transformers aren't necessary for your 160 meter Beverage b ecause your coax is only five meters long, b ut its probably best to use a pair of transformers. I ts likely that the l
Hi Ray, Suggest you use two porcelain insulators in series. I have some long porcelain insulators that might be a better long term solution. 73 Frank W3LPL -- Original Message -- I need the experienc
Hi Trevor, Simply terminate the high impedance side of your transformer in a 470 ohm resistor (or almost any other resistor) and use an antenna analyzer to measure the input impedance of the transfor
I wind matching transformers for receiving antennas with 30 AWG wire wrap wire. A BN73-202 binocular core will accept up to 18 full turns (36 passes). The insulation is very tough and it will not sho
Hi Terry, 500 pf "doorknob" capacitors are not rated for carrying significant RF current. They work great in high impedance applications such as plate blocking capacitor but in low impedance circuits