DITB,
For questions on specific problems with your
radio and/or
reception, it is
much better to start a new thread (with a subject asking the main question or explaining the problem)....
But until then, here are some brief recommendations / possible solutions...
1) I have no idea (and possibly neither do you?) whether your M-802 was ever working / installed properly....but let's assume that it is/was....
2) The AT-140 is a good tuner, but it does have a few peculiarities...
Sometimes / in some conditions / depending on
antenna length / depending on the RF
Antenna Ground system, it can attempt a "tune", but not actually get a correct tune/match...
Sometimes, pressing the TUNE button again will get a good tune/match, but sometimes you should try changing the transmit freq by about 100khz or so, press TUNE again, and try to obtain a tune/match (this should work)...and then return to your channel/freq of choice, and you should be fine and/or press TUNE there as well, and should be fine...
If none of the above works, then you should start a new thread here with as much info on your radio (serial number, install date, whether you have personally seen it
work on all bands/freqs in the past, and if so has anything changed since then, etc. etc.), your antenna (rope-tenna, whip, etc.), your RF ground / Antenna Ground, how/where the radio gets its 12vdc
power (directly from the main house bank, I assume?), where are you coaxial and tuner control
wiring run, do you have a "line isolator" on the coaxial line (at the AT-140 end), how many and where are your ferrites installed, etc. etc. etc. what channels / freqs
work fine and which ones don't, is this consistent or intermittent (fyi, intermittent problems can be a pin to find/solve, but many are caused by RFI, which is why "line isolators" and ferrites are so important)..
With this info, and as much more as you can tell us, we should be able to help...
3) Most playing around with NAVTEX
reception (on-shore) will use 516.3khz USB (or 516.1khz) and 1700hz (or 1900hz) as their "center freq", when using
SSB and a computer sound-card to receive NAVTEX....
When tuning it at the correct time, you should
hear the tones loud and clear! (if not, there is a problem)
But, your exact settings all depends on your set-up (????) and
software (????)....and you should follow the instructions that you have from the
software and
hardware suppliers, not mine...
I have no idea what App you have, nor how they work....so you should look at the App's instructions...
{fyi, most on-board will use a NAVTEX receiver designed for this purpose....never heard of anyone on-board using their
phone for this....just seems counter-productive, as it defeats the entire purpose/design of the NAVTEX system (simple/reliable/automatic/, etc.)}
4) I haven't been in
Hong Kong in almost 20 years (2 weeks in June 1997, for UK/Sino hand-over), but according to the info I have:
Hong Kong NAVTEX on 518khz (in English) is on schedule "L"...
Character B1 is "L", and the transmit schedule is:
0150z, 0550z, 0950z, 1350z, 1750z, 2150z...(that's "z"/UTC/GMT)
(not sure they use their entire 10 minute time slot, so you will need to make sure you're in front of the radio at those times...and this is why I don't know of anyone on-board a
boat that uses their radio to receive NAVTEX....everyone I know uses a NAVTEX receiver on-board, as it is automatic and saves the forecasts for you, automatically...)
5) BTW, in addition to the "M-802 Videos", here are some that should help...
HF-DSC
Communications
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX
Offshore Weather
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY
Maritime HF Communications (in general)
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y
And, of course, the
Icom M-802 Instruction Video Playlist
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr
Hope this helps???
Fair winds...
John