Icom AH-4 tuner

[Vesta]

Who has a radiostation setup with an Icom AH-4 tuner into a longwire and uses it to operate in the maritime MW band ? I'd like to know if its capable of tuning in the MW band (2182KHz) and if it does, what minimum antenna wire lenght must be. (TRx will be an Icom IC-7200)

TIA

w fr greetings, Leo

[ronstory]

The AH-4 supported freq is 3.5-54Mhz. You will be below the min frequency.

[Vesta]

That's the stated frequency range with a 7m (minimum lenght) antenna wire, is the range also limited by the tuner controller regardless of sufficient wire length? I have searched for a decent description but info on the tuner is very limited ;(

w fr greetings, Leo (PA5LS)

[ronstory]

The tuning is done through switches, coils and caps. You would need a different combo of coils and caps... and since the it's microprocessor controlled... you would need to do a lot of work to make it happen.

https://www.hamoperator.com/Hamopera...formation.html

has a decent overview of operation.

[RaymondR]

I have an AH-4 connected to mt Icom IC-78 feeding into a backstay and it appears to work OK although I have not tried it on 2182.

The fairly limited instructions have a note which states:

"The AH-4 can be used with most of Icom HF tranceiver, which cover HF through 50MHz bands. However the IC706 and IC736 can only be tuned in the 3.5-30 MHz range."

[Vesta]

Thank you for the info Ron, Raymond.

Best thing for us to do is to arrange a setup with an IC-7200 and an AH-4 to see what it is capable off. Had such a thing sitting in my shack a couple of years ago but didn't try marine bands then let alone the MW band ! Murphy at your service ...

w fr greetings, Leo

[ka4wja]

Leo,
As you've found out, although the "specs" show 3.5mhz as its lowest spec'd freq, the AH-4 may work lower with longer antenna....you could give it a try...BUT...
But, I'm wondering why??

If you're in Europe, there are many MF coast stations, but they do not maintain a voice radio watch on 2182....only 2187.5khz DSC...
And, your IC-7200 is a ham radio, not a marine radio, so it has no DSC modem/circuitry in it!
So, even if you can get the AH-4 to match your wire on 2182, there is nobody listening for your call...
(not to mention illegal to use on the marine freqs, unless in emergency)

If you're in US, on the high seas, Aus, NZ, etc., etc., there is nobody monitoring 2182khz either! And haven't been in a LONG time...
(with the exception of Bermuda Harbour Radio, who just last week confirmed that they do monitor it, but prefer VHF, or 4125khz, and do not get hardly any MF/2182 calls...they simply have 2182 available for Sea Area A2 comms when needed, such as if they receive a MF-DSC call)


So, they questions are:
a) who do wish to communicate with?? where??
b) why not use a marine transceiver w/ MF/HF-DSC?? (yes, they are pricey, but useful)


Have a look here for some further info:

http://www.cruisersforum.com/forums/...ml#post2592165


Hope this helps.

Fair winds.

John

[Vesta]

hi John,

not only do I have a full amateur radio license (old-fashioned with CW ), I also have a full ITU/SOLAS long range certificate so I can legally operate on both amateur- and maritime bands.

We do have a DSC capable MW/HF and VHF maritime station, the setup I am asking about is 1/ for amateur use and 2/ a possible backup for the GMDSS station as there is no Inmarsat or other satellite equipment (yet).

MW is still in use, but a lot of is intership traffic between fishermen and between coasters, especially if you go north a bit over here. Dutch coastguard for one still has Rx on 2182kHz, be it unofficial.

w fr greetings, Leo

[ka4wja]

Leo,
Wasn't trying to imply you were doing anything wrong....just wanted to make sure you understood the limitations (which you do)....and especially remind others here that 2182 isn't monitored by just about anyone, anymore...

(the USCG sent out special notices reminding mariners of this, and they still run into this misconception over here, and from seasoned / experienced / licensed mariners... )

Here is their alert from last August:
https://www.navcen.uscg.gov/pdf/marc...yAlert0817.pdf


Fair winds and good luck...
Please let is know how the AH-4 tunes up down there....I used to have an AH-2 with an IC-735 mobile, about 30 years ago...worked well, but never tried 160m with it...
(yes, I too am fully licensed...with cw, too...hi, hi...)


John