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rover67
12-17-2010, 02:25 PM
I want an antenna for the garage and for camp that will extend the range of my VX-7R. Right now with the mag mount antenna on a pie plate I can't hit Colorado Connection from my house in Boulder. That's kinda crummy.

When I met Kurt in the Swell for the Overnighter I noticed he was using a J-Pole, so that got me thinking... I need one to. It seemed to work well. I have a pine tree outside the garage I want to put it in.

So I dug a little bit and found these instructions:

http://www.alpharubicon.com/elect/jpolejaden.htm

A few questions....

Can I add a threaded connection in the main mast (halfway up section "a") that I can take it apart at? I seem to remember that Kurt Had his put together like that.

Also, what coax should I use? Seems like there are a ton of options out there.

Seldom Seen
12-17-2010, 02:58 PM
A few questions....

Can I add a threaded connection in the main mast (halfway up section "a") that I can take it apart at? I seem to remember that Kurt Had his put together like that.

Also, what coax should I use? Seems like there are a ton of options out there.

Yes you can put a threaded coupling in the long element for easier transport.

For a portable setup I'd use the shortest run of 8X coax as possible. 8X is the same OD as RG58 and but is more flexible, plus it has less loss at V/UHF. 8x ain't perfect, but it will certainly get the job done.

With the price of copper these days (unless you have some laying around) and the time building and tuning, I'd put my money down on another one of These (http://www.arrowantennas.com/osj/j-pole.html). Plug and play, no tuning and it gives you 440 which opens up 100's more repeaters. You can even order it with a threaded joint in the long element.

Edit: looks like Dave beat me to it on the coax. The 310 machine is above Golden just outside Golden Gate State Park.

nakman
12-17-2010, 03:10 PM
your 145.145 repeater is the Squaw Mountain one, eh.

and the 145.310 should be completely reachable from Marco's house in Boulder, I don't think there's a shadow.. I can hit it easily from the mobile rig in the truck so HT+J-Pole should definitely do it, IMO. :beer:

Bruce Miller
12-17-2010, 04:31 PM
I use the Arrow Antenna Model 146-4S, a 4 element 2 meter beam. Arrow Antennas are built in Cheyenne. The workmanship is excellent and the prices are very reasonable. The assembly directions are good and they offer a full, no hassle refund. The owner at Arrow is an excellent machinist with old fashion values. I highly recommend any of their products.

Convert
12-18-2010, 07:51 AM
x3 on the Arrow j pole been using mine for a couple of years now

CO Hunter
12-18-2010, 08:18 AM
For me and my son the fun was in building them, especially as new HAMs. We made j-poles from copper as well as some twin lead, both work well. Both seem to work on 440 as well, but we have not done extensive testing. However, having a friend with a good antenna analyzer is important for proper tuning.

smslavin
12-18-2010, 09:04 AM
FWIW, if anyone is ever interested in tinkering, please do not hesitate to drop me a line and I'd be happy to do what I can.

I may do that once we move, if that's okay. I'm reading a lot but theory only takes you so far.

rover67
12-18-2010, 03:44 PM
Well, I threw the first one together last night. It cost about $15 for the copper from home depot. The Arrow ones sure look nice, I kind-of think I could just get one of those for $35 and call it a day. On the other hand, I feel like making another J-Pole with copper from the depot and having it be the one I take places.

I still need to play with the antenna to see if it works, haven't really had a chance yet.

Oh, and I did end up getting the 8X coax... the guys at HRO pointed me in that direction. I was torn between that stuff and something else a bit thicker that they said was really nice. The guys at HRO were really a hoot to talk to. I stuck around there for about 20 minutes just chatting with them.

But dang, those arrow ones look nice...

rover67
12-18-2010, 09:10 PM
OK, tonight I put the second one together... I was a lot more careful with this one and got all the lengths as perfect as I could for 146.460.

I noticed I soldered the connector on the old antenna backwards... the shield to the main element. Also, for the new one I used electrical solder and flux. one of the websites said not to use plumbing stuff since it does not work well when an electrical current passes through it.

I also noticed that I didn't have the CTCSS tone set right on my vx-7r. I set it right and was able to get the 145.310 CCON repeater to work from my house. The smaller HT mounted antennas still didn't work, but again the J-Pole allowed me to at least get the repeater to respond when I "kerchunked". Tomorrow I'll key up and try to see what the signal strength going into it is by trying to transmit.

Hulk
12-20-2010, 10:20 PM
I have the Arrow Antenna J-Pole (http://www.arrowantennas.com/osj/j-pole.html) mounted on the back of my house. I can talk to folks all over the front range on simplex with it, and our house is in a valley.

When I mounted it, I had a few questions about grounding and called the guys up at Arrow Antenna. They answered the phone and talked to me -- you can't beat talking with an expert!

rover67
12-20-2010, 10:35 PM
What wattage do you run to it Matt?

I think Boulder is a particularly bad spot.... the guys at HRO confirmed it too.

Hulk
12-20-2010, 10:56 PM
What wattage do you run to it Matt?

A full 5 watts. (I just hook it up to my VX-7R.)

nakman
12-21-2010, 09:21 AM
I ordered an Aarow last night.. got the kit that will break down and shove into the bag. Will find a cool way to mount this to the truck or camper...

my ultimate goal being Colorado Connection from Moab, I wasn't able to hit it with the homebrew Yagi last year from BFE, so we'll give this a shot.

Seldom Seen
12-21-2010, 03:11 PM
my ultimate goal being Colorado Connection from Moab, I wasn't able to hit it with the homebrew Yagi last year from BFE, so we'll give this a shot.

Might be easier to access the Sinbad Desert AMC (http://www.ecso.com/sdarc/index.html) repeater system and bring up an IRLP link to where ever you want.

rover67
12-21-2010, 04:07 PM
yeah, I went with a J-Pole because on the house there is no ground plane, wanted something cheap (it was a $20 project including the connector), wanted to make it myself, and I like the way they look.

I ended up with two, one not so perfect as the other, and one that looks nice and works pretty well. I can get into the CCon repeater here in boulder but once I open it up it is only scratchyness that get's through. The folks at HRO told me about another antenna near Jeffco airport that takes a different tone to get into. I am going to try that next. I think I am in some sort of funky "shadow" here in boulder.

nakman
12-21-2010, 04:50 PM
yeah, I went with a J-Pole because on the house there is no ground plane, wanted something cheap (it was a $20 project including the connector), wanted to make it myself, and I like the way they look.

I ended up with two, one not so perfect as the other, and one that looks nice and works pretty well. I can get into the CCon repeater here in boulder but once I open it up it is only scratchyness that get's through. The folks at HRO told me about another antenna near Jeffco airport that takes a different tone to get into. I am going to try that next. I think I am in some sort of funky "shadow" here in boulder.

Hey that's a good point.. I think it's still 145.310 but you're at 107hz instead of 123hz? I can't remember, but if you listen on one of the 7:30 nets they'll probably say.

edit: ok Dave is faster, and probably righter. :)

rover67
12-21-2010, 07:27 PM
The Broomfield machine is 145.310-, 100Hz tone. It's a RX-only for the system, so if your shadow causes your reception to be scratchy then it won't help (it does not retransmit 145.310, just listens to 144.710). It's job is to help primarily Boulder hams when they TX to get into the machine.

Yeah, my reception is very very good. I just can't transmit

And yeah, now that you say it, the HRO guys said it was a 100Hz tone.

CO Hunter
12-24-2010, 08:39 AM
Last weekend I was doing some work on my laptop and happened to fire up Orbitron on a whim and saw AO51 in range. I tuned into the downlink frequency 435.300. I was able to clearly hear satellite traffic on the J-pole (2- meter tuned). Unfortunately I don't have much experience with the VX5 (my sons and he was out of town) so I couldn't figure out how to switch over the the up link frequency quickly enough before it was gone (RX on one freq TX on another). Point is I'm happy with the j pole on 70 cm. As for portability the j-pole, one made from twin lead would easily coil up and fit in a glove box, cost would be about one dollar/antenna. (300 ohm twin lead is cheap). Buy a coil of it and have an antenna making party at a meeting.

As for the hope the Arrow j-pole will do better than the home brew yagi, I'm no expert but I don't see how that cold be possible, unless there was a problem with the yagi. Just thinking theory of directional vs. omni-directional.

This forum is great :cheers:

nakman
12-24-2010, 09:00 AM
Well my issues with the yagi were likely beyond antenna principles.. for one it's made from PVC and allows some of the beams inside to slide, which probably puts the SWR all over the place. And worse I was using more PVC as a tower, which was great in the calm back yard but when brought out to windy BFE it flopped like crazy, made for an almost dangerous situation... :hill: :yagi: :hill: I ended up pulling it down and didn't mess with it much.

So I'm pushing for a more robust setup for next year. BTW, I received my Arrow J-Pole on Wednesday... very well built and in my hands 2 days after I ordered it. In hindsight I probably didn't need the bag, it's about 3x larger than it needs to be, but ah well it will still pack into the truck or camper just fine.

nakman
12-24-2010, 10:11 AM
Which bag did you get Tim? If it's the one with a bunch of individual pockets or slots, let me know if you want to sell it. I have the Arrow satellite yagi and having a dedicated bag instead dumping it all into one big bag would be handy.

What I'm think is this one:
http://www.arrowantennas.com/gfx/bag1.gif (http://www.arrowantennas.com/main/bag.html)

I got the other one, which is nothing more than a camping chair stuff sack.. for some reason I thought the one you show would be too small for their collapsible J-pole.. which I think it is. Too bad as that other bag is more of a tool kit and would be a much better thing to have.

rover67
12-24-2010, 12:48 PM
I kinda want an Arrow Yagi now.

nakman
12-29-2010, 08:12 AM
KD0MZE and I got a few QSO's in last night with the J-Pole.. I was running 1 watt from my VX-3r HT, using a ridiculously long length of coax. Nothing revolutionary, caught a couple guys on the 145.310 repeater who both said our signal was nice and clear. Good to go!

rover67
12-29-2010, 09:20 AM
Grr....

I wonder what the hell is up with my crap then.

I must really be in a bad spot... I still haven't done the 100Hz tone thing..

CardinalFJ60
12-29-2010, 10:55 AM
so impressed, I got online and bought the arrow jpole last night. Not only was there a mile of coax, the antenna was on the ground (vertical of course). the RX was clear as a bell. Waaaay cool.

nakman
12-29-2010, 12:03 PM
Grr....

I wonder what the hell is up with my crap then.

I must really be in a bad spot... I still haven't done the 100Hz tone thing..

I'll bring this over to your house some time... if it can hit the .310 and your crap can't, well there you go we've isolated the issue.. :D

rover67
12-29-2010, 12:51 PM
I'll bring this over to your house some time... if it can hit the .310 and your crap can't, well there you go we've isolated the issue.. :D

good idea :)

or maybe i need a :yagi:

CardinalFJ60
12-30-2010, 07:08 AM
I was messin' with my new HT last night and hit K0NAK from my living room on .310/123hz but scratchy....then he suggested the other tone. worlds better. That might just be your ticket. BTW...UPS is showing up today with my Arrow antenna. :cool:

rover67
12-30-2010, 11:32 PM
Here's whats funny, I checked what tone my radio was set to on the 145.310 repeater and it was actually set at 100Hz..... So I thought I was done for. I changed it to 123Hz just for kicks and I was actually able to hit the repeater and talk to K0NAK so I consider it a total success.

I guess a while back I figured out about the 100Hz thing and changed it when I was trying to hit the repeater with the bigger diamond antenna (HT Mounted)and just forgot about it.

Anyways, this was all still with my home made J-Pole stuck in the fence in the back yard. Mission accomplished I think.... Tim did let me borrow his new Arrow J-Pole so I am going to do a little comparison of the two later.

rover67
01-04-2011, 07:00 PM
Well I have to say I am pleased!!! I was able to talk to KC0PEG on his way home and try out both the arrow J-Pole and my Plumbers special J-Pole.... from what Dave said the Plumbers special was as good if not maybe a touch better than the Arrow!!

Sweet!!

I am stoked that it works as well as the Arrow, and that I can talk on the CCON from the kitchen! Mission accomplished! Maybe now to make a Yagi!

rover67
01-06-2011, 06:10 PM
pics of the antenna!

I need some input here.... do you HAM guys thing it would be OK to put a threaded joint like I did for the bottom part on the main part of the antenna to make it break down a little bit more? My only concerns are that the threaded portion is tapered so over time the overall length of the radiating element may get a bit shorter.... that and maybe the union is not cylindrical so maybe it'd make it radiate funky.

What do you guys think?

EDIT: I just reread my thread and realized that this was one of the first questions I asked!!! Sorry!

xodeuce
01-08-2011, 12:24 PM
pics of the antenna!

I need some input here.... do you HAM guys thing it would be OK to put a threaded joint like I did for the bottom part on the main part of the antenna to make it break down a little bit more? My only concerns are that the threaded portion is tapered so over time the overall length of the radiating element may get a bit shorter.... that and maybe the union is not cylindrical so maybe it'd make it radiate funky.

What do you guys think?

EDIT: I just reread my thread and realized that this was one of the first questions I asked!!! Sorry!

The length of pipe below the T fitting doesn't matter. It can be short, or you can U-Bolt it to a metal mast which would make it electrically much longer. The radiating element is wholly contained above the T as I understand it. I think if you're DC grounded below the T, you need a balun to keep the coax from radiating. Something like 4-5 turns of coax around a PVC pipe at the feed point of the antenna.

-Keith

Seldom Seen
01-08-2011, 06:53 PM
pics of the antenna!

I need some input here.... do you HAM guys thing it would be OK to put a threaded joint like I did for the bottom part on the main part of the antenna to make it break down a little bit more? My only concerns are that the threaded portion is tapered so over time the overall length of the radiating element may get a bit shorter.... that and maybe the union is not cylindrical so maybe it'd make it radiate funky.

What do you guys think?

I wouldn't over think it, just do it. The copper cactus is much more broad banded than its twin lead counterparts. Slight differences in OAL and diameter aren't going to make big changes in its resonance.

Choke baluns are never a bad idea, I like to use ferrite snap on beads (mix 43 iirc)

rover67
01-08-2011, 07:03 PM
I coiled the coax about 5 times near the connector.

I'll look for a ferrite snap on thinggie!

Thanks for the feedback! and it's nice to see you on here Keith!

xodeuce
01-09-2011, 08:11 AM
I coiled the coax about 5 times near the connector.

I'll look for a ferrite snap on thinggie!

Thanks for the feedback! and it's nice to see you on here Keith!

I've been lurking around your FJ40 resto page for a while. Figured I'd finally go ahead and join.

Good looking antenna you built there. We just started a 2M simplex net in B'ham, and it's got me wanting to get something outside and up high.

CO Hunter
01-09-2011, 08:25 AM
[QUOTE= Slight differences in OAL and diameter aren't going to make big changes in its resonance.

[/QUOTE]

FWIW, during construction of mine we put in a small screw on the short end to fine tune the copper j-pole. Additionally, the number of coax coils, diameter and location/orientation at the bottom of the "J" made differences in the impedance. We tuned it for the center of the 2-m band at 50 ohms. Antenna analyzer was MFJ-259B, I believe. Unfortunately I don't remember the ranges of these changes but I do remember the differences were enough for us to pursue changes.

jacdaw
01-09-2011, 08:40 AM
The Broomfield machine is 145.310-, 100Hz tone. It's a RX-only for the system, so if your shadow causes your reception to be scratchy then it won't help (it does not retransmit 145.310, just listens to 144.710). It's job is to help primarily Boulder hams when they TX to get into the machine.Does 531 have multiple voting receivers?

nakman
01-09-2011, 12:23 PM
Marco, that antenna sounds 10x better on simplex than it does the repeater.. nice work, man, better than a soup can on a string, that's for sure.

bvb
01-09-2011, 05:16 PM
Got my arrow 70cm/2m up today, hooked the FT60 to it and wow! I can hit the repeaters and simplex seem to be much better signal. Low power gets in to the repeater with no problem. Ready for the weather to turn and make us have to hang around the house and monitor the radio. :beer:

CardinalFJ60
01-09-2011, 06:36 PM
I was messin' around with my new arrow setup and it is nice to have a decent antenna on an HT. sounds quite good...I made contact with KD0NIC on the connection on Saturday.

nakman
01-09-2011, 08:34 PM
Hey Shawn are you messing with it tonight? let me know if you want to try simplex.. send me a text or something.

84cruzer
01-09-2011, 10:26 PM
http://www.youtube.com/watch?v=-fo-W1wDXHA



:lmao: