Before you do anything else, be absolutely sure you have your 505's "SSB" switch ON....it is on the side, just above the headphone jack.
(I use a ATS-909, and it works great....but, have never seen/used a "505"...)
I'm not sure of your exact location, nor intimately familiar with where you will be sailing, vs. VMC....
But, in general VMC is about ~ 550 - 600 from "NSW Central Coast"...
So, your first two steps are:
a) determine what freq to tune to for the distance...
b) determine what freq to tune to for the time-of-day...
I would try 11030khz and/or 13920khz, daytime....(typically from about 2 hours after sunrise, to about an hour after sunset...)
also try 5100khz in early morning and late afternoon/evening...
For nighttime, try 5100khz, and 2628khz....
(in brief...11mhz daytime is primary and 5mhz nighttime is primary)
Just about any length of wire, between 15' - 40', will work for you....
Originally Posted by Bruce K
I am trying to receive weather
on a Sangean ATS 505, from VMC in Charleville Aust. Attached whip is not great, now using a wire antenna via ext ant jack, any advice from HF gurus on length, this is receive only. Difficult to get much height, as I have no mast.
but, if you wish to optimize things, try 20' for the daytime and maybe double that length at night...BUT...
But, it is NOT critical at all!!!
And, if you have no mast???
Try just supporting this wire above the deck, horizontally, keeping it about 15' - 30' above the water...and you will have a great receive antenna!!!
If you had a mast, I'd say just clip a short wire from a shroud
/ backstay to the radio's ext. antenna jack...
But, without a mast and rigging
, try the wire I describe above...
Australia Weather East - Charleville ( VMC) Specifications
VMC & VMW Radio Fax Schedule
HF Marine Radio Services
But, the keys here are:
a) Getting away from all the RFI (Radio Frequency Interference) / radio noise generated by so many consumer and industrial sources!!!
Try your radio when at least 1/2 to 1 mile offshore
/ away from civilization....
b) Ridding your own boat of offending RFI...(see the links on both SSB
receivers / receive only, and links about RFI, in the "sticky" right at the top of the Marine Electronics
Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, etc.)
c) Knowing when / what freqs to use (see above and the videos linked to here..)
d) Please have a look at these videos....not 100% on point for your application in Aus, but pretty darn close!!!
(especially watch the first video here in this playlist, to get an idea of how radiowaves propagate on different frequencies / times-of-day...)
Bruce, once you've read the above, read the links, and watched the videos....you should be good to go!
P.S. I haven't tuned in VMC / VMW weFax transmissions in a while....but, I DO use their Voice Weather broadcasts (on 12362 and 12365, daytimes, and 8176 at night) as my "test" of how good radio propagation conditions are for me around the world....and remember, I'm > 9000 miles away from VMC, and about 11,000 miles from VMW....