Author Topic: N9TAX Slim Jims in VHF/UHF  (Read 8379 times)

Offline Canadian Prepper

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 54
  • New TSP Forum member
N9TAX Slim Jims in VHF/UHF
« on: June 03, 2015, 08:32:07 PM »
Hopefully I'll get enough of an opportunity to practice so as to be able to provide a worthwhile review soon, but I just got two N9TAX Slim Jim antennas with 16 feet of coax in VHF and UHF. I got one with the PL239 connector and another with the SMA female used on Baofeng HTs along with an adapter from SMA female to PL239.

At least one of these antennas will be packed away into my HT go bag and the other is currently being used in my QTH on my FT-897D for when I want to operate on 2m/70cm. The Workman UVS200 antenna that I've got for those two bands is currently exhibiting high SWR and will have to wait until a friend comes by with his SWR meter to figure out and hopefully fix, but given that I'd want a Slim Jim for portable use I'm going to try it on all of the local nets and repeaters in the upcoming weeks.

So far I've had a nice QSO with someone off of our main repeater and checked into an net on another one shortly afterwards. I was only using 5W and had hung the antenna right outside of a doorway with lots of metal siding nearby, but will try t get it into a better position soon. It will also be interesting to see how far I can get with the Baofengs attached to one of these. They are surprisingly compact when rolled up and can easily fit into even a small go kit.

At under $30 each and with stateside shipping, these products seem to offer a great deal of capabilities for less than the cost of a single UV5R. I'm keeping my fingers crossed that I'll find the time to test and review them more thoroughly in the coming weeks.

Offline Ken325

  • Survivalist Mentor
  • *****
  • Posts: 620
  • Karma: 47
  • "Winter is Coming"
Re: N9TAX Slim Jims in VHF/UHF
« Reply #1 on: June 03, 2015, 10:34:58 PM »
I did the same thing you did about a month ago. I bought one N9TAX slimJim, and I hung the antenna in the attic above my 2nd floor (3 stories high). I then ran 30 feet of LMR 400 coax to my office.  I hung it vertically about 7 feet from anything metal using zip ties and paracord.  I am in a HOA so no external antennas.  I can hit repeaters at least 20 miles away but I haven't tried further than that yet.  I had good results listening with this antenna using my baofeng UV5R and an adapter.  Much better than the rubber duck.  Then I passed my technician license about 2 weeks ago.  I would give my new call sign but it appears that you can look up my address if I do that, so my call sign will not be associated with my prepping unless I really trust someone.   I bought a Kenwood TMD710GA after passing the test.  It was $140 off because of the Dayton ham show.  That is an expensive radio for a first real radio, but I like the detachable face plate and  I am interested in using digital modes.  With the discount it was close enough to the TM-71A to justify the cost increase.  I have been listening to Fo-time, and the Partisan Radio podcast on pod bean.  It is associated with AMMRON  and it is hard core prepper communications that is very focused on how to do things.  Stuff like setting up a burner phone, encryption, encoding and decoding messages.  Good stuff and I highly recommend it you are not listening already.  Anyway I am very new to ham and I am trying to figure out stuff.  Is there a way to listen to a repeater that is out of range (45 miles)?  I know I can hit a repeater and push my signal out further but can I listen further?  I need to figure out stuff like echo link.  Anyway, I started putting a comm's box together for all my radio gear that I would want to take on a bug out.  I bought a second N9TAX slim jim with the 16 foot coax for my com's box. Gurilliacom on youtube did a great review of this antenna https://www.youtube.com/watch?v=gk9kgi__cE0.

I do have a question for more experienced hams.  I have an engineer friend who says I have to have a ground on both ends of the coax or the coax will act like a antenna and it will mess up performance.  The antenna is in a difficult place in my attic and I see no way to put in a ground other than punch through the outer wall in the attic and run a ground down 3 floors.  The ground would be at least 50 feet long and the HOA may complain if I do this.  I was told on this forum under a thread on antenna problems that this antenna does not require additional grounding.  It seems to be working well.  The highest SWR has been 1.6 and the performance is about what I expected.  Any opinions on the need for a ground and do I need to do something on both ends of the coax?  Also, I put a 1/2" ferriet bead on the coax about 4 feet below the antenna. No reason that I thought this was required, but it is dam hard to get into the attic in this location, so I thought I would take preventive steps just in case.  It sounds like the ferriet is not harmful just stops RF interference from traveling on the outside of the coax.  Opinions wanted if you have one. 

Offline FreeLancer

  • Global Moderator
  • Survival Veteran
  • ******
  • Posts: 5646
  • Karma: 759
Re: N9TAX Slim Jims in VHF/UHF
« Reply #2 on: June 03, 2015, 11:23:17 PM »
I like mine, all three of them.

Offline SCWolverine

  • Survivalist Mentor
  • *****
  • Posts: 541
  • Karma: 65
Re: N9TAX Slim Jims in VHF/UHF
« Reply #3 on: June 04, 2015, 06:35:54 AM »
I used the N9TAX as my primary base antenna for almost a year when i first got in.  It combined with my Wouxun HT (the cheap HT of it's time at $120) worked very well.

I too have the 16' coax version, and mine is terminated with a BNC.  Actually, I use BNC for most everything that I buy manufactured.  It's easy and convenient.

The design of the N9TAX and Ed Fong Jpoles (all J Poles I believe) do not require a ground due to it's design.

Thanks for listening to Fo Time, and I concur that JJS is doing a nice job on his Partisan Radio Show.

You can change your address to a PO Box if you are interested.  Everyone knows me, but I'd encourage you not to share your call anywhere online that you don't feel comfortable.  The change of address can be handled on the FCC site, and the POB offers you some insulating anonymity for very little cost.

SCW


edit to add:

to listen further you may have to go to a directional sort of antenna.  There are some low cost yagis that could be installed in an attic space, and even mounted to a rotator therein.  The yagi design would allow more 'gain' and may increase your signal reception and transmission (vs. your J-pole)

ex: http://www.cheapham.com/htek-dual-band-2m-70cm-yagi/

your J-pole is an omni directional antenna (receives on all sides) whereas a yagi or other directional antenna receives best from the direction it's 'pointing at'.  to add a different antenna, you'd also need an additional run of coax and maybe coax switch in the shack.

you can also hombrew a yagi if you are interested!
« Last Edit: June 04, 2015, 06:48:53 AM by SCWolverine »

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13111
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: N9TAX Slim Jims in VHF/UHF
« Reply #4 on: June 04, 2015, 07:31:13 AM »
Is there a way to listen to a repeater that is out of range (45 miles)? 

 I have an engineer friend who says I have to have a ground on both ends of the coax or the coax will act like a antenna and it will mess up performance. 

Is there a way to listen to a repeater that is out of range (45 miles)?   

If you could do this ...it would not be out of range.  ::) VHF and UHF are LINE OF SIGHT radio...
basically you must be able to 'see' the receiver antenna...
DIRT is a bad conductor of radio signal and the curvature of the earth,Hills,mountains all will BLOCK your radio signal
when they get between you and the receive antenna.The earth is not flat and for two guys on foot and "flat" ground,
the limit that you can talk with VHF/UHF is about 5 to 7 miles and higher power does little to help as dirt is good at
getting in the way.(So being mobile is not so much better than hand held except for a bit of antenna efficiency.
 To talk farther,the antenna on one or both ends need to be higher to see farther ...How high??

Using the line of sight calculator we see NOTE that when you include a repeater in the middile,the height of the repeater is the limiting factor...though you will not use repeaters much in SECRET as most repeaters cost big money and club membership helps pay that cost.
You will also find the value of community with clubs/repeaters  and being know to others as you won't get far with no one at the other end.

BOTH antennas at 6 feet give a range (due to curvature of earth)            of 6 miles
One at 6 feet and one at 30 feet (typical base to hand held or mobile)        11 miles
Repeaters are placed in high spots for a reason (a 200 foot tall repeater)   23 miles
The tallest repeater in my area is at 1000 feet (up on a TV station tower)   48 Miles

At longer range (15 mile plus) path loss will begin to also limit how far you can talk so at that point power will help,though not
as much as you may think..IE TEN TIMES the power will NOT double the range ...though when 'they ' have noisy signal the
power increase will help clear up you readability .

VHF and UHF are used for LOCAL communications for a reason as ,on earth base stations, they are limited.
As co-holder (it takes two) of the world record over land VHF record ,( NW Louisiana to central Maine) I know a bit about getting VHF to work ,though a lot of LUCK was involved.


Line of sight calculator:  http://www.qsl.net/kd4sai/distance.html


Your second ? of a GROUND  , NO it is not helpful or even beneficial for your antenna.Though the ferrite bead IS a good thing for the reasons you gave with RF interference.


And reading ahead I see SCW suggest a YAGI and while this helps ,you need height above ground with the yagi to get best results and a rotator as the YAGI received in one direction best (though ,one direction may be all you want)
« Last Edit: June 04, 2015, 07:38:06 AM by Carl »

Offline Ken325

  • Survivalist Mentor
  • *****
  • Posts: 620
  • Karma: 47
  • "Winter is Coming"
Re: N9TAX Slim Jims in VHF/UHF
« Reply #5 on: June 04, 2015, 09:35:50 AM »

I think I understand curvature of the earth and effect on VHF but the additional information helps.  I was actually curious if there is an alternate method of listening.  I am really interested in the AMMRON stuff and they have a net for the DFW area.  The problem is the repeater is in Plano about 40 miles away and I cannot hear it.  So, I was wondering if you could listen through a repeater or use a computer to listen to a distant repeater.  I remember reading something about setting up a chain of repeaters so you can pass a message across long distances.  Like I was saying I am interested in learning about ecolink, APRS, and digital modes.  (good topics for someone doing a podcast?)  I would like to see how these could be used for prepping.  A lot of people talk about APRS like it is a great thing. As I understand it, APRS is just a way of attaching your GPS location and other information like your call sign to your transmission.  I’m not sure that is helpful and I am afraid to set it up till I understand how to make sure it is turned off.  In a grid down situation I do not want to broadcast my position.  I am interested in digital modes because they are less easy for a casual listener to intercept, they appear to have better range (at least on HF), and you can transfer data.  I have a lot of beginner questions.  I should start another thread rather than hijack this one.

Offline SCWolverine

  • Survivalist Mentor
  • *****
  • Posts: 541
  • Karma: 65
Re: N9TAX Slim Jims in VHF/UHF
« Reply #6 on: June 04, 2015, 10:16:55 AM »
Good Idea, start another thread and we'll smother you with our opinions  8)

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13111
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: N9TAX Slim Jims in VHF/UHF
« Reply #7 on: June 04, 2015, 10:31:06 AM »
Radio and PC are two different mediums of communications.
Look up the Plano repeater that AMRON uses and search for streaming audio.
A repeater does not automatically exist on the internet,it has to be "put" there.
Also some radio scanner groups 'put' streaming audio on the internet also.

Echo Link also  has some repeaters connected and this may be a way....
but their is no "given" in how to use the PC to listen to radio as they are different worlds.

The problem with interconnected repeaters is the quantity of gear tied up and only one at a time can speak ...
like telephone party lines of the past (not the $3.99 a minute kind)

I used APRS 20 years ago and beside your position,messages can be sent and received...though other digital modes may be better.
PACKET may be of interest ,though it also is old and we keep getting more and more modes to use that operators get spread out.
Your best bet for emergency type use is VOICE as there are more people learning to talk these days ,(this may sound like a joke but I assure you ,it is not) Any mode you use that is not voice further limits who can or will respond and often those who do hear you will not reply unless they KNOW YOU and this is why community and being part of the local Ham club is pretty much a necessity to build adequate skill and local contacts to be of future (and current) value.


As far as broadcasting your position...you have no way to talk without being FOUND quickly on Ham radio...if you want to be a secret squirrel ,your radio has very little utility for you...you can just listen...the radio is like your rifle....and your radio active friends that you communicate with and share time with are the BULLETS...as a lone wolf ,you will die with help close by....this is why things like encryption are of little use unless your group has enough members and supply to be fully self supporting.

The real value of Ham radio has nothing to do with SECRETS...it is COMMUNITY.

Two cans and a string are what you need to not be known....but pray someone is near the other can. Hams have strength in numbers .
Listen to FOTIME podcast 24 and you will learn a bit more on emergency communications,but I only have been doing this over 25 years ..There is little place for digital in a true emergency as it takes time and equipment to set up frequencies and modes and often train users in the skill needed...though I fully agree that fewer nefarious types will hears you and digital is an excellent way to pass data with less openness.

I can perhaps focus better on your need and offer information with a bit more detail in a PM from you. I need not know your call sign as I do keep my radio world and digital world separated a little...though not to the paranoid level.

All I can offer is what works from my experience and guide you with suggestion with what details you provide.

I hope he reads this too,it took some time for me to type. SCW ,I just read ahead.

Offline Leaky Waders

  • Fledgling Prepper
  • *
  • Posts: 1
  • Karma: 0
  • New TSP Forum member
Re: N9TAX Slim Jims in VHF/UHF
« Reply #8 on: June 23, 2015, 11:27:51 PM »
I have emailed Joe from N9TAX three times and have not received a reply. I placed an order for a slim jim a few days ago via Pay Pal and have not received any information from the seller. Does anyone know if Joe is out of town or experiencing an issue that would prevent him from communicating about an order?

Offline Smurf Hunter

  • Survival Veteran
  • ********
  • Posts: 7013
  • Karma: 329
Re: N9TAX Slim Jims in VHF/UHF
« Reply #9 on: June 24, 2015, 12:09:38 PM »
This coming field day our EMComm team is holding a public workshop to build these roll-up Jpoles.  We have a variety of end connectors, so people can make them with BNC, SMA or standard UHF connectors.  We're charging $10 per person to cover the parts.  The hope is to attract other hams and the public at large.

Rumor is the mayor will stop by for a photo op.   ::)

Offline jerseyboy

  • Survivalist Mentor
  • *****
  • Posts: 539
  • Karma: 28
  • Garden State Prepper
Re: N9TAX Slim Jims in VHF/UHF
« Reply #10 on: June 25, 2015, 07:04:07 PM »

Rumor is the mayor will stop by for a photo op.   ::)

100 points for the elected official.  You also get 100 points if the police come out but only if you invite them and not because you strung your field day antenna from your neighbor's house  :)

Jerseyboy

Offline Smurf Hunter

  • Survival Veteran
  • ********
  • Posts: 7013
  • Karma: 329
Re: N9TAX Slim Jims in VHF/UHF
« Reply #11 on: June 25, 2015, 10:19:48 PM »
100 points for the elected official.  You also get 100 points if the police come out but only if you invite them and not because you strung your field day antenna from your neighbor's house  :)

Jerseyboy

Even without making a single contact we should have 1000 points.  We also have some members < 18 yrs old that helps a little.

Open house is 1-3pm if anyone is in the area ;)

Offline Canadian Prepper

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 54
  • New TSP Forum member
Re: N9TAX Slim Jims in VHF/UHF
« Reply #12 on: November 10, 2015, 01:24:11 PM »
I packed my Slim Jim for an ARES/Red Cross SET last weekend and used it instead of the rooftop antenna to run the 70cm net (I was using an easily reachable repeater on 5W). Lo and behold, the other operator on the 2m Simplex net discovered that there's a problem with the rooftop antenna causing high SWR. at which point I loaned him my second Slim Jim. Given how small and light they are even with the 16ft of coax, they'll never stay at home again.

Offline 13 January

  • Fledgling Prepper
  • *
  • Posts: 5
  • Karma: 0
  • New TSP Forum member
Re: N9TAX Slim Jims in VHF/UHF
« Reply #13 on: December 18, 2015, 04:20:26 PM »
Have been using the dual band N9TAX for years as my base station UHF/VHF antenna. Love it!

Offline Alan Georges

  • Survival Demonstrator
  • *******
  • Posts: 4455
  • Karma: 208
  • Still trying to reason with hurricane season.
Re: N9TAX Slim Jims in VHF/UHF
« Reply #14 on: December 18, 2015, 04:52:55 PM »
DIY version thread: http://thesurvivalpodcast.com/forum/index.php?topic=50529.0

I did build a couple of these, but if I need anymore of them I'll probably just order from N9TAX.  They'll probably be better made, and it'll free up some badly needed spare time.