| KB6HRT |
Rating:  |
2002-05-07 | |
| WORKS VERY WELL |
Time Owned: 0 to 3 months. |
| Brought AH-4 yesterday and installed it on an old .64 R/S antenna which is a ground plane antenna 22 high with four 9 foot ground planes. Had to mod antenna bypassing matching network for 11 meters, The antenna I was using before was a Cushcraft R 6000 Vertical ( A very good antenna in its own right.)The R6000 does 6-20 meter with 1.2 SWR or better on all bands it will work. The AH-4 matched 6 meters at about 1.7 SWR or less across the hole 6 meter band. 10 meters 1.6 or less, 12 meters 1.6 across the band, but 6,10 & 12 has a lot more gain than the R6000 so brought in the signals a lot stronger and my antenna output was up a lot on 100 watts. All stations came back to me FIRST TRY That did not happen with the R6000 on a 100 watts 15 meters match 1.2 17 meters 1.2 SWR 20meter down 2S units from my inverted V SWR 1.2 40 meters SWR 1.2 down 4S units and 80 meters 5+ S units SWR 1.5 but will tune from 39.50- 4000 at 1.5 SWR. The R6000 will take 1KW the AH-4 120 watts with out getting in phones and TV. |
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| KE4OAR |
Rating: |
2002-01-03 | |
| Well Pleased |
Time Owned: 6 to 12 months. |
As an update to my report in Feb, 2001, I am pleased with the AH-4 Tuner and IC-706MKIIG combo in my truck.
I mounted the tuner under/behind the rear jump seat and mounted the antenna on the rear bumper. Although the tuner is "water proof" and I would not hesitate to place it outdoors in a fixed location, the environemnt of an automobile might be taxing for the AH-4's water proof capabilities. Besides, it was a lot "sexier" installation where I put it.
I have tried a CB whip as well as 20m and 40m amstick antennas and the tunner will tune all of them from 40m thru 6m. I prefer the hamsticks because they don't flop around in the breeze as bad as the CB antenna.
I have not done comparison tests between the different antennas at the same time on the same band, but I have made contacts without any problems on all three antennas on various bands, even on 6m with the hamsticks.
I've found this set up has worked as well as my FT-900 with hamsticks on the old car and it is great not having to stop and get out of the car to change bands! |
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| JA7UDE |
Rating: |
2002-01-03 | |
| Another happy user |
Time Owned: more than 12 months. |
| I have been using AH-4 with IC-756 for four years and am very happy with it. I have a 40-meter loop wire connected to the hot and cold terminals of AH-4. The wire is just hooked on the top of several trees in the backyard. It gives me a snappy match from 160m to 6m including WARC bands, though 160m is out of the spec. If you have a trouble in tuning, try adding a common-mode choke to the coax and control cables as closely to the AH-4 as possible. AH-4 is about a half size of the former model, AH-3. I would recommend this lunch box to all. |
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| WB4M |
Rating: |
2001-12-25 | |
| Another satisfied user. |
Time Owned: 0 to 3 months. |
I finally got around to installing my Icom 706MKIIG in my SUV, and completed the setup with an Icom AH-4 tuner and a stainless steel whip from Radio Shack. My first attempt at using the tuner was impressive.. I tuned to 20 meter phone band, keyed the microphone, and the AH-4 clicked 3 times and the whip was tuned! It took less than 2 or 3 seconds! Icom recommends retuning if the frequency is changed even a little, so I moved up to 14.300, hit the mic button again, and almost instantly the whip was retuned. I ran across a small pileup on a special event station and made one call and the station answered me and gave me a 59 report.
I then went to different bands (40 thru 10 mtrs) and the tuning was just as fast as I experienced on 20 meters. This tuned makes mobile operation a snap and I am very impressed with it. If you are looking for a mobile tuner, this is the one to buy. |
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| N0RU |
Rating: |
2001-11-07 | |
| Excellant |
Time Owned: 0 to 3 months. |
After purchasing a new truck and not wanting the "Russian Trawler" look, I decided to try the AH-4 and a simple 9ft whip. At first, I had some problems with 20 and 17 with RF back into the radio. I tried re-routing cables, changing grounding points, and adding toroids on the control line. What finally solved my problem was a simple coaxial RF choke. I wound 10 turns of 8X at the input of the tuner..problem solved.
The tuner will match the fiberglass whip from 80-6, but the vswr on 80 is high (expected). Since my main interest is 17 and above, this is not an issue.
The tuner is mounted inside the bed of the truck which has a fiberglass cover on it. The tuner is constructed to be waterproof, but I would not want to mount it under a vehicle in my area due to salt spray in winter.
In summary, if you want a simple set-up that will allow you to operate bands without changing separate whips or wandering leads, give the AH-4 a serious look. Add a $14 whip from your friendly RS and have fun. |
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| WA3RA |
Rating: |
2001-10-15 | |
| Outstanding Performance! |
Time Owned: 0 to 3 months. |
I finally had a chance to put my new AH-4 through the wringer during the PA QSO party this weekend, mostly on 40 meters, but with some forays into the 75 meter fray.
I am using this tuner with a 706MKIIg, which is my 'backup' mobile HF rig (main use is 6 meters)
I have mounted the unit inside of the minivan on the passenger rear side, and I am feeding a military whip (132 inches / 336 cm) mounted on the side of the van with 40KV wire (total feed length is about six inches, which IS part of the antenna).
This critter found a suitable tuning solution every bit as fast as my big-bucks setup, and performed almost as well, signal-wise!
I also have an SGC-QMS3 system with the matching whip mounted on my vehicle (on the driver's side)which is and will remain my main system (due mainly to it's ability to tune and work on 75/80 and 160m).
For use from 40 meters and up, I would not hesitate to recommend the AH-4 in a heartbeat!
It does play on 75 m, but the efficiency is only on the order of about 1 percent or so, which is just too low for reliable use from the car.
I'll be buying another of these guys for use from the house with either a loop or a long-wire!
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| K8SWD |
Rating: |
2001-10-05 | |
| Nice little coupler |
Time Owned: 6 to 12 months. |
I normally run a 500 watt SGC system mobile and my SGC235 watt coupler died on me. My SGC230 coupler was already in use at home. Deer season was fast approaching and I knew I would not get my beloved SGC coupler repaired or replaced in time for my hunting trip, so I bought the AH-4 to put on my vehicle. (SGC did send me a brand new SGC235 500 watt coupler--good company!) I had both an IC-706MKII and an IC-706MKIIG. I mounted the coupler to an aluminum plate bolted to my luggage rack on my Suburban, along with a ball mount and 102" stainless whip. I ran ground braid to the body and drilled holes behind the rear vents above the tail lights. The coupler worked real well 40 to 10 meters. 6 meters was not quite to my expectations, but 102" plus 6" spring is a half wave length on 6 meters and that should be avoided. I think that is why the Icom whip is shorter. I added a foot of mast and had no problems and got better results down lower. This coupler is not rated to tune 80 or 160 meters on a whip antenna. I got poor results on 80 meters with the 102" whip, although the coupler would match it. The AH-4 worked great loading a shorty Hustler mast and 80 meter coil, however. The Hustler coil and mast did not work well at all on the other bands.
I notice at the top of this page this coupler is listed as 160 meter capable. Icom does not advertise this. I would not chance it, especially with a any wire less than a quarterwave on 160. This coupler is not rated to match lower than 7 MHz with an antenna less than 23 feet. This coupler is NOT an SGC230 or SGC235 coupler! Stay within the specifications!
On the down side, this coupler only has 45 memories and you lose them when you cut power. Non-volatile memory would be nice. The SGC230 has 500 non-volatile memories. The AH-4 only works with IC-706 series radios, and a few other Icoms. It does not give you 6 meters with the original 706. It is not rated for 160 meters. The SGC230 will out match the AH-4 by quite a bit, but it costs almost twice as much and does not have 6 meters. The SGC will work with any radio.
On the good side, this coupler is only about $250.00 now and is a great little addition for what it can do. Light weight and very portable. It withstood a Michigan winter no problem. Just make sure your ground is good and large as compared to your antenna, and DO NOT use coax on the coupler out put! |
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| K9EQ |
Rating: |
2001-08-07 | |
| Better than Aluminum |
Time Owned: 6 to 12 months. |
I've been running the AH-4 since February with both the loop and flat top configurations. It consistently works well on all bands. I make virtually every DX contact I attempt. The AH-4 and a few bucks worth of wire is, in my opinion, a much better investment than a vertical.
The real blast with owning a remote tuner like the AH-4, is that you can design and build antennas and you don't have to worry (much) about the feedpoint impedance. You can concentrate on gain and pattern which are, after all, what we really care about.
Why is the AH-4 better than other remote tuners?
1. It only radiates 350 mw while tuning.
2. The Tx generates about 10 watts during tuning. This power is dumped into a resistive power divider. The radio sees 1:1 SWR during the tuning process.
3. The tuning relays never switch "under load". No more arching and burnt contacts.
4. It uses a Pi configuration with 22 C and L values - it will tune almost anything.
5. It can be used with a balanced output.
The downside, is that it must handshake with the radio and "out of the box" it only works with a couple of Icom radios. I've created an "Unofficial AH-4" web page to collect information about this product:
http://www.hamoperator.com/ah4/AH4.htm
73's
K9EQ
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| HK3THI |
Rating: |
2001-08-06 | |
| 5/5 |
Time Owned: more than 12 months. |
I HAVE BEEN USING THIS TUNER FOR SEVERAL YEARS ,
WITH THE ICOM 706 KII,ESPECIALLY THE WEEKEND IN OUTDOOR .
iT IS WORKING GREAT IN EVERY WAY ,I WAS IN SAN ANDRES ISLAND USING A 10 M WIRE AND TALKING TO ALMOST ALL THE CONTINENTS!!!!IN ALL THE BANDS!!!
160M TO 6 M NO PROBLEMS.
MY FRIEND HK3JJH PEDRO USED MY TUNER IN MALPELO
ISLAND A COUPLE OF MONTH AGO AND ALSO WAS SUPRISED
OF THE PERFORMANCE OF THIS PLASTIC BOX.
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| K6NFL |
Rating: |
2001-08-06 | |
| My solution for all HF band |
Time Owned: 0 to 3 months. |
| I really like this unit. I use it with the ICOM 746. I live in one of those nieghborhoods that have antenna restrictions. My solution was to mount the AH-4 high on my patio cover. Then I ran a wire around the top of the patio cover, using about 120 feet of wire in a loop antenna. Noise is greatly reduced over the dipole I was using and I'm pulling in more stations than I ever had with the dipole! Icom says you can tune up from 80-6 meters. I can also tune up on 160 as well as all the other bands. Tuning is easy, just hit the tune button on the 746 and the tuner just matches the frequecy to the wire. |
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