Throwable Antenna?

[Destro]

Just curious, is there a type of antenna that you can throw up in a tree? So like, when I'm camping, is there like a wire type antenna that I could use a throw rope or something like that to hoist it up high in a tree and connect to my HT?

Looking for something that would preferably work on GMRS and 70cm/2m. Don't even know if something like this exists.

[SteveShannon]

2 minutes ago, Destro said:

Just curious, is there a type of antenna that you can throw up in a tree? So like, when I'm camping, is there like a wire type antenna that I could use a throw rope or something like that to hoist it up high in a tree and connect to my HT?

Looking for something that would preferably work on GMRS and 70cm/2m. Don't even know if something like this exists.

One of the most convenient antennas to do that with is the j-pole antenna made from flat lead cable. You can find plans or you can buy them from various places. One of the earliest developers of this roll-up j-pole was Ed Fong. He has his college students make them. Just google Ed Fong roll-up j-pole for GMRS. 
Some people like them; some don’t. 

[radioruck]

The Ed Fong DBJ-2 was designed for this. He makes different models, one tuned for 2m/70cm ham bands and one for GMRS/MURS. He doesn’t sell them direct on his site but mentions distributors who does.

(I have one of the GMRS models I’m not using. If you’re interested, post a wanted thread in the Miscellaneous forum to keep with the site rules.)

[Destro]

22 minutes ago, SteveShannon said:

One of the most convenient antennas to do that with is the j-pole antenna made from flat lead cable. You can find plans or you can buy them from various places. One of the earliest developers of this roll-up j-pole was Ed Fong. He has his college students make them. Just google Ed Fong roll-up j-pole for GMRS. 
Some people like them; some don’t. 

Thanks, I'll check it out. I also just stumbled upon the vfcomms Fara-J roll up antenna. That might also work for me too. Only thing is, it doesn't look dual band. They have several different ones, like GMRS, 70cm, 1.25. 

[BoxCar]

Almost any antenna can be strung up. You'll need to use a nonconducting string or rope. Fishing line like Spiderwire is best.

[Destro]

Just now, radioruck said:

The Ed Fong DBJ-2 was designed for this. He makes different models, one tuned for 2m/70cm ham bands and one for GMRS/MURS. He doesn’t sell them direct on his site but mentions distributors who does.

(I have one of the GMRS models I’m not using. If you’re interested, post a wanted thread in the Miscellaneous forum to keep with the site rules.)

Oh that would be great. I'll do that.

[WRYZ926]

Another option is to make or buy a j pole antenna made from faraday clothe. Super light and rolls up smaller that most wire j pole antennas. 

Here is a link fara-j-antenna-for-gmrs

That website has them for 6m, 1.25m, 2m, 70cm, and GMRS. Or you can find the plans online and make your own. I made my own and it works well.

A wire or faraday clothe j pole will work for you.

[Destro]

1 hour ago, radioruck said:

 

(I have one of the GMRS models I’m not using. If you’re interested, post a wanted thread in the Miscellaneous forum to keep with the site rules.)

I posted it in the Miscellaneous forum.

[Destro]

10 minutes ago, WRYZ926 said:

Another option is to make or buy a j pole antenna made from faraday clothe. Super light and rolls up smaller that most wire j pole antennas. 

Here is a link fara-j-antenna-for-gmrs

That website has them for 6m, 1.25m, 2m, 70cm, and GMRS. Or you can find the plans online and make your own. I made my own and it works well.

A wire or faraday clothe j pole will work for you.

Yes, I stumbled upon these. These look good as well.

[WRYZ926]

The faraday clothe antennas do work and they roll up nice and small. I've been impressed with them. I bought one for GMRS and then built one for 2m. 

[SteveShannon]

3 hours ago, Destro said:

Thanks, I'll check it out. I also just stumbled upon the vfcomms Fara-J roll up antenna. That might also work for me too. Only thing is, it doesn't look dual band. They have several different ones, like GMRS, 70cm, 1.25. 

Ed Fong has written articles explaining how his J-pole antennas work. He has designed and sells dual band j-poles. 

[TNWEB]

https://www.n9tax.com slimjim works well for me 2m/70cm

[Lscott]

1 hour ago, TNWEB said:

https://www.n9tax.com slimjim works well for me 2m/70cm

I ran an SWR sweep on the MURS/GMRS version. 

On MURS it looks really good.

On GMRS the match was barely OK around the 462MHz region, and good at 467MHz where the repeater frequencies are located.

I did the same for the Ham 2M/70cm version.

I wouldn't use it below 436MHz on 70cm. Above that to 450MHz it looks OK.

On 2M it looks fine across the whole band.

 

N9TAX-MURS-GMRS-UHF Scan.pdf N9TAX-MURS-GMRS-VHF Scan.pdf N9TAX-2M-70CM-UHF Scan.pdf N9TAX-2M-70CM-VHF Scan.pdf

[WRTC928]

I have a J-pole made from 1/2" copper water pipe and a roll of parachute cord to throw over a limb and hoist it up. It works really well. I don't have one of the roll-up J-pole antennas because I just throw it in the truck, but if you want to pack it all into an ammo can, that might be a good option.

[WRDJ205]

On 10/2/2025 at 7:22 PM, WRYZ926 said:

The faraday clothe antennas do work and they roll up nice and small. I've been impressed with them. I bought one for GMRS and then built one for 2m. 

I’ve been watching a lot of the YouTube videos on the Fara-J antennas.  I have not seen a lot of discussion about a good coax that would balance flexibility and losses.  Seems like RG316 is preferred by some but it looks like it has some significant loss (not surprising though).  
 

Any thoughts about coax cable for this application?  

[WRDJ205]

Found this…

But, I’m still curious about the RG316 if anyone has experience with it.  

[WRYZ926]

I normally don't hang mine from a tree so I don't worry about the weight of the coax hanging from the connector. I use a telescoping mast with mine. I use velcro straps to hold the faraday clothe j pole and coax to the mast.

RG316 is going to be very lossy at 70cm and GMRS frequencies.

Here are some loss numbers per 100 foot.

RG 316 - 17.568 dB

RG 58 - 13.698 dB

RG 8X - 8.485 dB

RG 8 - 4.61 dB

LMR400 - 2.741 dB

So if you use a 5 watt HT with a 20 foot coax here are the actual ERP numbers with an antenna that has 1 dBd of gain.

RG 316 - 2.8 watts

RG58 - 3.3 watts

RG 8X - 4.3 watts

RG 8 - 5.1 watts

LMR400 - 5.5 watts.

I used the following website to get those numbers:

https://mjars.org/training/tools/52-line-loss-calculator

[WRDJ205]

28 minutes ago, WRYZ926 said:

Here are some loss numbers per 100 foot.

This is perfect!!  Thanks. 

[WRYZ926]

You're welcome.

I don't know what the actual gain is of the Fara-J antennas. Most j pole antennas are rated around 2.15 to 2.2 dBi which equals 0 to 0.5 dBm of gain. I used 1 dBd for that calculator I linked.

As the antenna gain goes up, so does the ERP output when using the same coax. That is why a beam antenna with high gain will always have a higher ERP compared to a dipole or j pole antenna.

 

I redid the numbers using 20 feet of RG-316 and a 5 watt radio. This time I use 0 dBd of gain

The EPR will be 2.2 watts using an antenna with 0 gain. Compare that to a Comet CA712EFC base antenna that is listed at 9 dBI. 9 dBI equals 6.86 dBd.

Using the same radio and same 20 feet of RG 316 with the CA712EFC will get you an ERP of 10.8 watts.

[WRDJ205]

I’m going to look around.  I have an RG 8X but I think it’s 50’.  I might get a 15-20’ of the RG 316 just to keep in a pack.  But I’ll likely use something else even if it’s just to keep it close to net 0 and have the same 5W as the 5W radio.  

[WRYZ926]

I have a 25 foot long RG 316 coax from ABR Industries. I bought it to use with my QRP HF radio to keep everything as small and light weight as possible. While the loss on the 10m band is not has high as loss on UHF, it's still a bit higher than I would like. But sometimes we have to make compromises to keep everything light and portable.

Even with a 50% loss when using a 20 foot RG-316 coax. You can still get out if the antenna is up in the air and has a clear line of sight.

[MarkInTampa]

On 10/3/2025 at 10:33 AM, Lscott said:

I ran an SWR sweep on the MURS/GMRS version. 

On MURS it looks really good.

On GMRS the match was barely OK around the 462MHz region, and good at 467MHz where the repeater frequencies are located.

I did the same for the Ham 2M/70cm version.

I wouldn't use it below 436MHz on 70cm. Above that to 450MHz it looks OK.

On 2M it looks fine across the whole band.

 

N9TAX-MURS-GMRS-UHF Scan.pdf 284.32 kB · 2 downloads N9TAX-MURS-GMRS-VHF Scan.pdf 284.88 kB · 3 downloads N9TAX-2M-70CM-UHF Scan.pdf 285.33 kB · 1 download N9TAX-2M-70CM-VHF Scan.pdf 285.04 kB · 1 download

Strange, my N9TAX GMRS/MURS sweep shows around a 1.3 SWR in both 462.5MHz and 467.5MHz in the GMRS band.

 

[Lscott]

1 hour ago, MarkInTampa said:

Strange, my N9TAX GMRS/MURS sweep shows around a 1.3 SWR in both 462.5MHz and 467.5MHz in the GMRS band.

 

That is a bit strange.

This might have more to do with the environment I tested the antennas in. I did pick these up at a Ham swap a couple years or so ago. That might be why the guy was selling them, not built right maybe.

I tested a homemade 300 ohm TV twin-lead version I built for 2M. It also showed a similar fast rise in SWR towards the low end of the band.

I did a simulation for a simple GMRS J-Pole a while back just for fun. It looks a lot like the results you got.

I guess I should take time and repeat the tests on the sample I have and do the testing out in the clear.