Author Topic: Boost antenna performance on Baofeng  (Read 7880 times)

Offline atherts

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Boost antenna performance on Baofeng
« on: October 17, 2014, 12:33:15 PM »
For those of you with handhelds like the Baofeng or equivalent.
I found this at http://sdrformariners.blogspot.com/p/blog-page_28.html
I used a piece of thin wire about 19" long. It does seem to make a difference.

To improve performance of any handheld antenna use the following:
Tiger tail, rat tail, counterpoise, same stuff, piece of wire connected to antenna ground: metal surrounding the center pin around the antenna socket.
Length should be 75 divided by MHz of interest, for maximum efficiency on marine channels use 20" / 50 cm length wire - if no measure available roughly three palm's length, wrist to elbow distance or shorter and longer side of regular A4 paper together.
Above 400 MHz use 7" / 17.5 cm length of wire, palm's length, safe bet.
Connect the wire to metal base, round wire connectors shown are a perfect fit. Plastic surrounding the socket needs to be cut, screw the antenna on and mark at the back of the radio first.
If using non-standard antennas, due to gap tiger tail is not flush and moves around, washers needed for a tight fit.
Tiger tail effectiveness: 50 % to 100 % improvement on both transmit and receive.

Offline backwoods_engineer

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Re: Boost antenna performance on Baofeng
« Reply #1 on: October 18, 2014, 08:28:18 AM »
The antenna that ships with the Baofeng is highly resistive, and therefore not very efficient.  It will start to get hot after transmitting awhile.  This is the inexpensive antenna I replaced the factory one with on my Baofeng UV-5R:

http://www.diamondantenna.net/srh77ca.html

It's available at most ham radio stores for about $25.  I bought mine in Austin, TX, while on a business trip.

Offline Fire Ant

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Re: Boost antenna performance on Baofeng
« Reply #2 on: November 15, 2014, 10:40:32 AM »
(posting in this thread because I have a Baofeng 5R and I am looking for a better antenna)

I am a newly licensed ham operator.

My purpose is for use in a disaster. (NOT a hobbyist, have too many hobbies already, and not enough time).

My question at this point is about HAM radio - I need someone with knowledge to tell me how to use the "Tech" level bands to communicate long range using man portable hand radios and antenna.  Think "Backpack" or "Hiking" radios.  Something you could carry on the Appalachian Trail. 

"Long" is a relative term... My Baofeng 5R can get 5-15 miles with the longer 15" antenna.  I am looking for 50-100 miles or even 500 miles. I heard/read that the antenna is more important than the watts and that it was possible to make an antenna that would accomplish this range, yet roll up to pocket size (dipole that could be hung in a tree? or was that j-pole?). Is this possible?

Every time I ask a local Ham Operator, they say to buy a big radio, amplifier, 100' tower and beam antenna and get a higher level license to transmit on 80 meter band. Tinker with this, tinker with that, build this.

To do that does not meet the mission -- it has to be portable AND affordable to the rank and file.

So, where do I find this "how-to" info?

(If you think it is impossible without going to 40 or 80 meter band with bulkier equipment -- please do not bother to answer, save the band width for those who have a solution or possible solution.  That will save space and time.  If no one answers, I will have my answer -- without reading 400 posts that just say "it can't be done")

Offline Carl

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Re: Boost antenna performance on Baofeng
« Reply #3 on: November 15, 2014, 12:24:37 PM »
FIREANT...I thought I answered this somewhere else here in the forum. But ,here are the cliff notes:  VHF/UHF is line of sight...that means it works like a flashlight and will transmit as you can see ..it will work about 7 mile with both at ground level and 25 miles with one at 200 feet above average terrain(like a repeater) and at 1000 feet you can often get 50-60 miles.

But HAM satellites are way up there and not to hard to work (when on is over you) plus a take-down beam made for back-packers by ARROW ANTENNAS will give your signal somr strength to be heard...it is  not an easy anytime option and a schedule of available birds and times will help a lot.

Also most wilderness areas monitor frequencies HAM/and FRS...some marine...so knowledge of those places and protocols will greatly improve you chance of being heard.Much how to info found with Google search.

About the best I can answer now from my hospital bed on 'borrowed' net access.

Offline Fire Ant

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Re: Boost antenna performance on Baofeng
« Reply #4 on: November 15, 2014, 02:38:17 PM »
Thanks Carl.  I will track down Arrow Antennas.

Offline Carl

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Re: Boost antenna performance on Baofeng
« Reply #5 on: November 15, 2014, 03:01:51 PM »
Thanks Carl.  I will track down Arrow Antennas.

Here   http://www.arrowantennas.com/

Offline Alan Georges

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Re: Boost antenna performance on Baofeng
« Reply #6 on: November 16, 2014, 01:12:08 PM »
Fire Ant, you may find this enlightening:
http://en.wikipedia.org/wiki/Line-of-sight_propagation#The_actual_service_range

Terrain, tall buildings, towers, and airborne repeaters (satellites, drones, etc.) can all be massive helps here.  Even with a LOS path, with a 5w HT you may need the gain boost of a beam antenna like Carl suggested.

Impossible?  No.  But to squeeze these kinds of ranges out you're going to have to get clever.  Comes a point where it's easier to say screw it and go to HF and NVIS.  There's no brick wall that proclaims "thou shalt not," just a bunch of engineering tradeoffs.

Offline Carl

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Re: Boost antenna performance on Baofeng
« Reply #7 on: November 16, 2014, 01:30:08 PM »
The first astronauts on the moon used ONE WATT VHF AM radios on their suits and talked to earth stations from 240,000 miles ///but I have to add they were in a pretty high location and the vacuum of space had little path loss.Also,a lot of people with big antennas were listening for them.././.do you have someone who will listen to you?

Offline armymars

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Re: Boost antenna performance on Baofeng
« Reply #8 on: November 16, 2014, 01:57:27 PM »
 I wonder if you could make  a repeater with a toy drone and a HT as a cross band repeater. Send it up a hundred feet with HT and use your HT the ground to relay through it.
  Otherwise were back to NVIS. Think Hendrix 80 meter SSB/CW QRP radio( $176) and end fed antenna or the new TJ5A YouKits 4 band HF radio. 20 watts $404 USD for no solder kit and battery, bag, filter.

Offline Carl

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Re: Boost antenna performance on Baofeng
« Reply #9 on: November 16, 2014, 02:04:55 PM »
I wonder if you could make  a repeater with a toy drone and a HT as a cross band repeater. Send it up a hundred feet with HT and use your HT the ground to relay through it.
  Otherwise were back to NVIS. Think Hendrix 80 meter SSB/CW QRP radio( $176) and end fed antenna or the new TJ5A YouKits 4 band HF radio. 20 watts $404 USD for no solder kit and battery, bag, filter.

A hundred feet high will get only a 25 mile footpriint (due to curvature of the earth) and you would need 1000 to 1200 feet up to get 50 to 60 mile sporadic coverage due to atmospheric path loss.

But VOICE and TECH frequencies were in the request so NVIS (though a good option) is out of the equation...


I must also add that the TIGER TAIL/ counterpoise at the very beginning (before the thread was re-directed) brings better balance to the radio/antenna pair(actually a dipole with the radio half being too short for best VHF use)
« Last Edit: November 16, 2014, 02:11:49 PM by Carl »

Offline Smurf Hunter

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Re: Boost antenna performance on Baofeng
« Reply #10 on: November 17, 2014, 12:45:01 PM »
All this is true.  My home is fortuitously located at 600ft above sea level, with direct unobstructed line of sight to a repeater @ ~1000ft over 50 miles away.  I can mostly hear this repeater using an out of box baofeng uv5r.  When I add a tuned 2meter JPole in my attic and use just 5watts on a FT2900R (2 meter mobile), I can have clear conversations in both directions.  What's also nice about this particular repeater, is folks in northern Oregon can hit it as well.  So that nets me almost 90 miles as the crow flies between 2 operators using that repeater.

Now, very few people live somewhere with repeaters at those altitudes and salt water between them.  But it does prove the point that with enough height above ground, modest power VHF can go pretty far.  While it's nice to get some fine gear to boost your capabilities, knowing what repeaters are available, and the geographical range they provide is critical in an emergency.  All that said, if that repeater goes down, then I'm back to a 20-50 mile circle depending on what other repeaters are operational.

Also, I have had mixed success with satellite comms.  I've been able to TX using the same jpole antenna and heard myself on 70cm using a scanner.  Those satellites move REALLY fast (~16kmph), so you only have 1-9 minutes of window where you can TX/RX.  There are free phone apps and webpages to assist with the schedules.

If you planned to leverage "birds" to increase your VHF distance it would take some pre-planning and coordination in advance.  Given the narrow window and the Doppler affect and shifting up/down frequencies by small amounts as it passes, I don't imagine a ton of folks just tune to a satellite's TX freq. and just listen all day.  Maybe I'm wrong...