VHF UHF antenna basics - DIY antennas from surplus 800mhz antennas for 2m 70cm and dual band 

I went back and watched it from the start. Good vid. Thanks for the info.

Thank you ! That's an old video - I have upgraded to an Anritsu CellMaster for antenna testing now that they are being surplused out so cheap . I'm glad you enjoyed the video. Antenna scrapping can be fun . Thanks for watching !

You are welcome ! I wanted the UHF length before the coil. I have not tried it the other way to see if it would work. BTW I still use this antenna on a mag mount when I use a rental car. Thanks for watching !

5/8 wave 800mhz antennas were all the rage in the smartzone and amps days and every one I have found will work if you extend the resonator as shown. Just find a 5/8 wave 800mhz (806-870) antenna and add length. These antennas pulled out of the pile unmodified are typically resonant around 160-170mhz just add a couple inches overall and your VHF is done. Thanks for watching

I have a nice set here. The whip was much smaller than the stand off. Would have had to seal it regardless. 5 + years later it's still working good. Thanks for watching !

I haven't as I was interested in keeping a compact profile but others have done it . I did have the hustler colinear 2m one 28 years ago and it was legit perfomance wise but enormous. Thanks for watching !

@@survivalcomms I can imagine it was long….

@@lawrence1md It is still available www.hamradio.com/detail.cfm?pid=H0-003363

You should look into building a collinear antenna for UHF or a yagi and away from a "dual band " solution IMHO. This is a resonant compromise. Thanks for watching !

You can totally make your own antenna in that fashion. You will need a resonator that you can solder , solder it to the center pin, insure that your resonator is insulated from the body of the connector. Thanks for watching !

@@survivalcomms Thanks! Any particular material I should use or is it good enough as long as it is insulated and the plug is filled up for sturdiness? Edit: Could I use the dielectricum in a coax cable and slip it on the resonator? If it's too tight I could split it and insert a strip of dielectricum in the split and fill up excessive space in the plug with non conductive silicon that hardens, for sturdiness and to prevent water to enter. I will have to find a resonator that will not bend easily and still fit the plug because I'm planning to put it on a magnetic base and use it on my car. It will not be for the ham bands. It will be for commercial frequencies in the ranges 154-160 MHz and 445-460 MHz. I will start with the measures from your videos and experiment from there, shorten it bit by bit. Do you think it's possible to make the antenna resonate in both the above mentioned frequency ranges? Any other comments on my plan? I can use all the advice I can get.

@@syspangylium some dielectric from RG8 should suffice

@@survivalcomms Thanks again! ☺️

You are welcome !

Cool beans ! Let me know how it works out ! Thanks for watching !

With old 800 antennas it wouldn't work out. It is possible with other antenna designs. If you want good performance go with monoband antennas IMHO. Thanks for watching !

Those will work. I have access to the rods. I just used the pile of surplus antennas I had to make the video. Thanks for watching !

I'm glad it helped you out. Thank you for watching !

The 5/8 wave cell antennas are resonant about 160 + - 5mhz in my experience. If you remove the finish , put a test clip on the top, and add a couple inches of wire adding length above the coil you can see if it helps. Thanks for watching !

Indeed it does ! Thank you and thanks for watching !

Cool ! It is always fun to make something useful. Thanks for watching !

Yes you can as long as you keep the antenna parameters within the VHF / UHF frequencies you wish to cover. Thanks for watching !

Thank you ! I am glad you enjoyed it. Thanks for watching !

You get my full respect, whenever there is a "Coil", a rule of thumb is "Trial and error", coils have very tedious and complicated formulas that takes lots of calculation and end up useless. You did a great job by kicking computing off the table. Saved us time & money and most important it works PERFECTLY !!!

I played around with what I had laying around at the time. I had lots of 5/8 800 antennas at the time. Since on the VHF side it was just a quarterwave it was pretty simple. Thanks again !

Back when I made this video I was using my buddy's MFJ 259. I try to keep my videos short and sometimes details get left out. The feedline connects from the antenna's NMO base and goes the the RF connector on the 259 in this example. I use an Anritsu Cellmaster now for VHF/UHF/SHF antennas and the antenna connection is on the RF out on that one. I hope this answers your question and thanks for watching !

Thank you ! Yes they can . Placing the nmo base on a sheet of metal with radials or using a commercial kit such as the Larsen BSA KIT (Tessco PN 38748) can adapt mobile antennas to fixed applications. Antennas adapted thus exhibit the same characteristics as they would mount on a vehicle. Thanks for watching !

Yes indeed it is conductive. Thanks for watching !

That is because it is a half wave radiator and not a quarter wave radiator. Thanks for watching

You are welcome ! Thanks for watching !

You could but it would not be completely efficient across that range. Thanks for watching !

There are lots of cheap UHF antennas out there. Which one is 47 bucks ? You can make a UHF quarter wave out of that scosche cb antenna pretty easily.

Is there any way you could make a video explaining how to make one? and I was talking for the magnetic base and the antenna whip itself

MSgt101 spin the spring off of the base and let me know what size the post is .

It doesnt sat what size it is but it is the same size on bothe ends and i only have the antenna not the base

so you have no magnet or feedline ?

NMO mount Thanks for watching !

Sebastian Tufigno No difference at all. If you have a solid connection you are good to go. Thanks for watching !

It transmits just fine. Still working fine today.

Thanks for watching !

Thank you and thanks for sharing !

The motor couplers were 3mm Thanks for watching !

Thank you for the fast response, 73 from KK4PGM

With the height of this base it was 5.75" When you look at the overall length of the whip and base over the NMO connector it was a tad over 6 inches. Thanks for watching !

@@survivalcomms thanks for responding 👍

@@jloaiza9188 You are welcome - anytime we can bend e-waste to our will it's a bonus.

The length beneath the loading coil will dictate your UHF resonance. The overall length will dictate the VHF. Do you have an old 5/8 800 mhz antenna you are working with ?

@@survivalcommso was thinking of buying some on ebay. just needed more understanding s othe rule is the bottom half is the uhf and the overall is the vhf .I want to get into understanding antennas during and emergency and you have to vacate be nice to know what you could use to get by with for antenna

The 800 5/8 waves can be pressed into service as VHF quarter waves if need be as is. In this circumstance the main consideration is to keep the length of the UHF at 1/4 wavelength below the loading coil. The overall length should equate to a 1/4 wavelength at VHF. The best practice is to test what you have to see where you are before you start cutting. You can always lop off 6 inches above the coil remove the coil and make a UHF antenna.

@@survivalcomms SurvivalComms explain the following to see if we understand 100%. If we put 6 inches or 1/4 of a wave into UHF we will have, for example, an antenna for the UHF resonator down below the charge coil. Now above the charge coil will have another 6 inch or 1/4 wave UHF resonator with the same measurement, okay?! Now what is the measure of this turn that lies in the middle of these two UHF resonators? What happens if this coil is larger or smaller in turns, and in turn the more coil (the coil) increases in size and the less the coil the smaller the coil. We want to understand the following: 1/4 wave of resonator at the base just after the magnetic base and before the charge coil, then the charge coil, after the charge coil another 1/4 wave resonator, is this? What is the purpose of the load coil because it is not responsible if the antenna will cover 1/4 wave in vhf. If 1/4 wave is used above and below the load coil, what is the purpose of the load coil? You can explain it better. Because we like antennas and understand how we can improve our own antennas. SurvivalComms Makes more videos with this antenna analyzer format, but specifically for GMH and vhf uhf. As this antenna has 6 inches of resonator, then has a coil of 6 turns and size approximately 6 centimeter, then has another resonator of 8.5 inches. So this type of antenna is more suited to UHF GMRS? To further increase the bandwidth of this antenna in GMH UHF, should you increase more the resonance or reduce, or even increase the number of coil or reduce? Because our idea is UHF GMRS / FRS, but to increase the bandwidth across the 70 cm range. Now if you have three resonators, will the antenna have a higher gain in uhf GMRS / FRS SurvivalComms?

This works so-so on UHF as well. The angle of radiation is not as good as it could be. Thanks for watching !

Keep your eyes peeled I'm going to do a video on antenna theory that might clear things up a bit. I will be happy to answer any specific questions on the subject matter as well. Thanks for watching !

You are welcome ! Thank you and thanks for watching !

Thanks for watching !

It you have close to 6 inches above the coil you are good cutting that off and using it as a 1/4 wave resonator on GMRS. Thanks for watching !

I have been doing that for years now. It is a great adjunct. I have it as part of my bugout bag radio video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-mbaIrpEWILg.html Thank you and thanks for watching !

I know I'm kind of randomly asking but does anyone know a good site to stream newly released movies online ?

@Enrique Dario i watch on flixzone. Just search on google for it :)

@Elisha Shawn definitely, I have been using flixzone for years myself =)

@Elisha Shawn Thanks, I went there and it seems like they got a lot of movies there =) Appreciate it !!

Thanks for watching !