Antenna Questions (

[@lyfandeth]

Dave, hard drives have a similar air problem. They need to be hermetically sealed to keep out dust, but still breath as they heat and cool. The solution is a 1/8th inch hole, covered by a dime sized piece of GoreTex. That allows air pressure to equalize, but blocks moisture, dust, etc. Some Pelican cases use the same design to equalize air pressure while remaining waterproof as well.

[@BretChilcott]

Dave, thank you for sharing your knowledge. These are very helpful videos. Keep up the good work!

[@3v068]

You have responded to me a couple of times, and I really want to thank you for taking the time to answer my questions that I've had so far. I have another one. I am running into an issue with radials and room in my back yard for certain placements. My back yard is rectangular and relatively thin as im in a residential area. Would making a choke end work for the room I have? Im trying to get into 40 meters with a quarter wave.

[@louisseaman8455]

Dave, you just made me think about the balun I put into an outdoor electrical box that is supposedly sealed from the weather; I may have to drill a weep-hole soon. Also, thinking about what you said about a tower being the antenna itself, I've heard they do that with commercial A.M. broadcast antennas, I wonder if the concrete base of a tower could be a decent enough insulator as long as it's dry, say, coated in epoxy, and shaped to shed water to the surrounding ground in the rain? Correct me if I'm wrong, but the other point of course is that if using the support itself, like a tower, as an antenna, getting the tower or whatever he's using as the radiating element, 'resonant', is a must for it to be effective for desired frequency of use, and then getting it to match the impedance needed; I think it's sometime lost on people new to antenna theory that you might have a good impedance according to your SWR meter, but that doesn't mean your antenna is resonant, and without it being resonant, you're losing effectiveness on receive and transmit.

[@RJWolfeStunts]

Great video Dave, 73!

[@tedclapham4833]

Dave, I at one time planned to have a four square for 160 metres. I had planned to use four 137 foot towers 18 inches on a side, this works out at about 110 degrees in length taking the length to diameter ration into consideration. The base is to be 15 ft off the ground with an elevated radial system. The feed point impedance of each tower at band centre is 50j+100. Each tower is Variable Capacitor fed. Each tower is shunted to ground with a high current choke with a minimum Inductive reactance of 5000 ohms. Each tower is fed through a auto SWR bridge that tunes the variable Capacitor for minimum SWR which if my design is correct will be 50j0 anywhere in the band plus or minus 5 ohms. This should also work for a single tower!

[@jerryturner7078]

I bought a MFJ_1778 10=80 meter G5RV but wanted a ZS6BWK. How much of a difference are there and can I adapt it to the ZS6BKW optimized G5RV? You do a great service and I enjoy your videos, thanks you. Jt

[@davidsradioroom9678]

Great advice.

[@invisalinkaccounts2740]

Dave, Love the channel and your informative videos. I have two questions, if you would be willing to toss your expertise at them. 1st, when I mount my Polyphaser or whatever brand lightning arresters in the box at the base of my tower, would you do them Vertically or Horizontally? and Why? I know you know much better than I, so I thought I'd check your Opinion. I want to keep my gear safe!!!! 2nd Question if you would. Could you recommend a 2m/70cm vertical antenna for my house? I have a 25'~ Tower outside my house (previously used for TV/Sat) and I plan on putting a 8' Pipe on it and a vertical antenna on the top if it. Later on I'll try HF. I'm considering the Comet GP-9 or the Diamond X510HDM, or is there something different you'd recommend? I do both weekly repeater nets and Simplex nets. I'd like to reach out as far as I can locally on 2m/70cm. I do worry about about the longevity of an antenna that long/tall flexing in the wind, but I want the reach. Thanks for your time Dave!!! I really appreciate it and look forward to more videos. Thanks and 73s to you. Scott

[@Ivan-dc9ex]

3:00 An empty champagne wine bottle (drink the wine with you friends before building an antenna :-)) makes a good bottom insulator for a mast used as a vertical antenna. Other types of glass jars seem to be too weak and break soon. 8:00 I disapprove that there is no mirroring in a coax. IMO electrons on the inner side of the braid mirror the movement of electrons in the center conductor. Electrons on the outer side of the braid shall not move at all! Similarly, in an unbalanced quarter wave vertical antenna, the movement of electrons in the mast (radiator) is mirrored by the movement of electrons in the groundplane. If the groundplane exhibits low conductance, the antenna becomes a crap.

[@toaddale7216]

I've ordered an MFJ-2286 big stick with the intent to talk on cb without sitting in a vehicle all day. My aim is to get some of my cb friends away from the shack and outside, sort of a cb POTA if you will. My question is will this antenna work for this application? I've also made a tripod system for a firestick IB5A tunable tip antenna and added ground radials. Are either of these a suitable option. Focus was portability and efficacy. Thanks in advance and 73!

[@scottfulton159]

I keep the tips of my dipoles at least 1 meter away from the support poles.

[@rickeaston3228]

Is there any kind of alphabetical index to your videos. Most of your videos are numbered and if there were an index showing topics with video number, it would be much easier to go back to something I saw previously. I'm probably not the only person that would like to see an index.

[@michsmi8297]

I think the tape is amalgamation tape elsewhere

[@mikeloce]

Great info Dave. 73 all. Mike, W1LOC.

[@saulsilver7462]

73 OG this was some gangster information on antennas woop! Woop!

[@MrJaz8088]

Q? 40meter is a long wire (1/4of 160mtr) ? , Then a 9-1 Balun is the answer for the first question ?

[@MrJaz8088]

Self Amalgamating Tape, and For a Sealed RF Box then you need Baking Soda or those Satchel's in shoes/ clothes ect, or a Mist Separator from a Air Line

[@fridayjoefriday]

Old time dead key ham operator used vaseline and q tips. Coat the center connector and threads of the connector, tighten. He unscrewed one connector, he claimed had been connected for twenty five years, no water, no corrosion, clean. Yes the coax looked old.

[@rogerlafrance6355]

Silicone Grease is what's used.

[@shaunsiz.itsbetterbytube2858]

Hope your ok Dave you sounded a bit out of salts .kind regards from over the pond

[@tld8102]

can i get some advice on antenna and radio? i’ve been tasked solve a problem. our 10000ft competition rocket is made of carbon fibre which blocks RF. we want a onboard FPV drone camera to stream a live video feed to the ground as it flys up. i’ve been thinking of making a custom helical antenna(chosen for it’s all all round coverage) that wraps around the outside of the rocket’s main body out of copper/foil tape? I have no experience at all. Are the decision we’ve made a bad idea so far? and how would i go about designing/making that antenna? i have no clue

[@skinnyflea2628]

I do not think that will work. I recommend getting a small fpv antenna if you are using 5.8Ghz and just try to find a way to get it outside. It could be up to an acrylic window even of course when the rocket rotated you will loose signal though. I hope this helps a little and you are able to find an answer.

[@tld8102]

@@skinnyflea2628 yeah... the engineerings don't like the idea of drilling holes into the rocket.

[@skinnyflea2628]

@@tld8102 I get that. I wish I could help more. Good luck.

[@tld8102]

@@skinnyflea2628 appreciate it

[@buzzsah]

Boaters use sealant tape, A boat supply store should have it.