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DB, Everything looks fine to me. Looking at what you have though, the whip is 102" + 6" +2" = 110" = 9.1666667'. 234/9.1666667 = 25.5273 MHz or so. Stray capacitance from the cable has shifted the resonance point to 29.66655 MHz. You will notice that resonance is where the phase = 0 (where...

Google 48" Stainless Steel Whip Antenna and you'll find several sources. The standard lengths for most whips are 24", 36", 48", 56", and 62", plus the 102" CB whip. Some come as straight whips, others are available as tapered whips. It seems the 48" lengths come either way. 73, Mike

I thought Public Safety was in favor of VHF/UHF/800 MHz and higher, but look at this: Intrado inks deal for 'Apocalypse-proof' HF offering | Intrado content from Urgent Communications

Go to Array Solutions: Baluns

Doc, What you are then saying is the device that connects a 50 ohm balanced dipole to 50 ohm unbalanced coax is not a balun (Balanced to Unbalanced) ,but just a choke?

Hi Doc, Get the book "Building and Using Baluns and Ununs" by Jerry Sevick, W2FMI. Section 1.3 describes the choking capabilities of a Guanella "choke" balun. In it, it states: "Several important points should be made regarding Guanella's 1:1 balun shown in Figure 1-2A. With sufficient...

Here's pictures of proper current baluns: one using parallel wire, and the other using coax. Both are designed for 50 ohms. The three wire Turrin balun shown above is a voltage balun that has no choking capability.

Then how do you make a 1:1 balun?

Doc, There are two ways to make a 1:1 choke or balun using either two parallel wires or coaxial cable. When making a Guanella (Current) balun you have either the parallel wires or coax wrapped around a ferrite rod or a ferrite core. This winding(s) requires tight bends that would destroy foam...

You need a 1:1 Current Balun or an RF choke. They're one in the same. If you use coax to build a choke, do not use cable with foam dielectric. Use one with polyurethane or Teflon to prevent the center conductor from migrating to the shield and shorting out. It won't happen immediately, but...

Getting the parts to finalize the construction. After then I can determine a price. Then will need to write manual and obtain packing material.

Here is a calculated horizontal polar plot. Gain is around 6 dBi, and F/B is -33 dB. The measured VSWR for the antenna shown is 1.1:1 at 50.150 MHz:

I hope this gets on the site. I have been having the same symptoms that Homer has with the Moxon design software. Namely the design frequency is higher than the actual operating frequency. The antenna was designed around 50.4 MHz, however the VSWR is lowest near 50 MHz. The goal is to have...

SAL Electronic is developing a 6 Meter Moxon. The antenna features 1/2” 0.058” hard drawn aluminum tubing, 1-1/2” square aluminum tubing, all stainless steel hardware, fiberglass insulation, and a 6 KW PEP balun. Yes!, that's 6 KW PEP or 3 KW AM (Continuous Carrier) operation. Thus, this Moxon...

Homer, Attached is a pdf of the pre-production version of the manual. It provides many parts dimensions, but nothing useful on the loop. Got the antenna around 1967 when Avanti first started in Addison, IL. Bought antenna from the owner. 73, Mike

The Antenna Specialist base station division was bought by Andrew Corporation, Orlando Park, IL a number of years ago. Attached is the current data sheet from Andrew. Ths web site sells the antenna: ASP7A Product Detail. Not cheap, but it is a commercial antenna meant to be cut to a particular...

Here's a brand new radio that does what you asked for: Uniden Bearcat 980 CB Radio with Sideband 73, Mike

For a good 50 ohm match use 1/4 wave radials. More specifically, 1/4 wave plus 5%, (234/F(MHz) x 1.05) at a 45 degree down tilt if possible. If the radials are straight out the impedance would be closer to 37 ohms or so. Mikie

You're confusing RF resonace with DC circuit theory. What is a direct DC short does not necessarily constitute a short at RF resonance. Depending on how you feed a dipole antenna you can see an open or short with an ohm meter. Connecting a dipole directly with coax and you will see a DC...

Just worked: IK2WZM, 28.4374,59 ZS1AFS, 28.552, 58 CU3AC, 28.525, 59 All on phone with 100 Watts and an 80M OCF at 20 ft. Mike