Nasa HF3 and weatherfax problems

[ColinR]

I am having no luck getting weatherfax via my Nasa HF3 radio and I would welcome advice from someone who has it working. I am in the Azores at the moment and this is supposed to be my means of getting weather info when out of navtex range. I have put a lot of time into this but so far not received a single weatherfax although I am getting voice stations from far afield.
After persevering for a long time with the active antenna and following advice from various quarters I have dispensed with it as it was picking up a lot of interference from other equipment. I now have about 12 metres of insulated single core wire cable-tied to the backstay. This connects via about 5 metres of coaxial going to the HF3. I am about to try separating this from the backstay in case running parallel with it is causing problems. The ground is connected it to my engine block. The HF3 is connected direct to the battery so it is separate from all other equipment and I can switch off all other systems while using it. I run the laptop on its own battery not via an inverter.
For software I am using Mscan Meteo and JVComm32. both seem to be working ok, picking up the sound input from the HF3
I have the correct times and frequencies for Northwood, Hamburg, Boston and Halifax and am tuning on USB just below the frequency trying all the available frequencies. I never get a good recognisable fax signal. I have tried it both in harbour and out at sea so as to be away from external interference. Its driving me crazy!
Any suggestions most welcome!
Many thanks, Colin

 

[Bilgediver]

If using JV32 have you tried different sotware settings as the software has to be set up and also you need to be on the correct side bands for the settings. You may also have to tune off the advised frequency as it is usual with fax and other data signals to publish the ACTUAL frequency of transmission however most ssb radios unless they have a DATA setting indicate the reduced carrier frequency so you may have to tune about 1400 hz off frequency. This does show up on most softwares as you will see you are OFF frequency when the tuning indicators on the screen say OK .

I will have to find a puter here with JV32 to see what the settings are as I have not used this in some time however if you are getting a clear signal you should have no problem unless the audio of the radio is not peaky enough.

 

[ccscott49]

Sorry, but I had the same problem and never received a fax. Sold it on. Bought an Icom computer contolled one, now I get them fine.

 

[whipper_snapper]

If you are not hearing a reasonably strong clear fax signal - you can find an example file here - then your computer settings or how you are connecting the hf3 to the laptop are irrelevant.

If you are not and have tried different freqs at different times, then the problem is the aerial or the radio's performance. Running a wire up the backstay is very commonly done for receive, you should be aware that in radio terms it is indistinguishable from electrically connecting it to the backstay. But it should work on a plastic boat provided you haven't done something special to ground your rig - eg for lighting protetion ? If you have then it is worth trying to separate your wire from the backstay by a few inches of air.

If that fails, you need a better receiver! There are cheap low power ham sets around that are useless as transmitters but have nice sensitive receivers.

 

[ShipsWoofy]

how are you connecting the hf3 to the laptop?

 

[ShipsWoofy]

[ QUOTE ]
Sorry, but I had the same problem and never received a fax. Sold it on. Bought an Icom computer contolled one, now I get them fine.

[/ QUOTE ]mine works fine

 

[mikejames]

A long time back I bought an HF3M and this was hopeless. Its concept dated from before every PC having a soundcard so it fed its signal in using the serial port of the PC, using a crude analog to digital converter. Now all PCs have soundcards, so I disconnected the analog to digital converter and routed the signal from the top of the volume control to another jack socket on the back panel. Then I used a modern weatherfax program on the analogue fixed level output which I had created and it worked better.

But the HF3 has a very cheap frequency synthesiser intended for shortwave tuners in European car radios in it, and this is noisy in itself and blurs things like weatherfax.

Spending the same kind of money on secondhand Japanese receivers will probably result in much better results.

 

[agurney]

I take a tap off my HF3's speaker, and put that into the laptop's line-in socket, then use wxsat to decode it. Use low volume on the HF3. Connect the co-ax braid to your boat's earth.

 

[TigaWave]

I've got an HF3 and you should be able to easily pick up the fax sound as in the link that whipper gave.

Feed this from the earphone jack into the mike sound input and it works well for me on an old Tosh Win98 and Mscan fax and text program.

Usually better reception away from harbours but it was usable in Horta and every other port from here to South america. I like it as it is easily portable and travels with me on other boats as an easy reliable weather receiver, along with laptop and gps.

Keep trying or find someone who has one in the Azores, there must be a few in yachts passing through. I, like others found using the sound card was better than the serial input advice it came with.

 

[Bilgediver]

I don t know what the stability and the tuning is like on the receiver you have however fax does require an ability to fine tune and stay on frequency.

I just loaded the latest JV software and boy has it grown. Won t run in my usual data PC , complains not enough memory so loaded in the lappy....Well initially had no joy using default settings for HF fax although I was putting a good signal into the sound card via the line input from a low level output on botyh a Yaesu and a sony...QAlmost sounded and looked like Northwood had RF bproblems which I have seen before especially when they transmit the block headers.

I then connected to the mic socket and what a difference.
I am wondering if the sound card is doing something to the line input as it produces a blurred trace although showing a full signal.
If you have a similar problem I would suggest that before ditching your receiver you try as another poster has suggested and take a feed from the volume control input to a socket on the back of the receiver and use this to feed your mic socket. you will need an outer volume control connection not the middle one. This will allow the volume to the computer to remain constant even if you turn the volume down.

It is possible that you puter will be happier with this clean signal and may print.

I an now getting crystal clear faxes from Northwood on 4608 using a Sony Sw55 portable so you should manage something.

 

[ShaunG]

Can you get a decent sounding signal without being connected to the laptop? If so i had a similar problem with the soundcard in my laptop. You need to go to sounds and mute all with the exception of the line in or mic input, whichever you are using. The laptop seem to add some power 'noise' over the signal if you do not mute the other inputs. I use SEATTY with my HF3 which seems to work better, although overall i am not that impressed with my HF3 and the signal is always noisy, It's not the aerial as when connected to a Loewe HF150 i borrowed it's crystal clear.

 

[hubert]

I use the HF3w with meteoscan lite and get excellent fax pictures and near continuous RTTY reception from DWD in germany.
First you have to decide what version of Hf3 you have. My original was HF3m which came with software called TARFAX which I used for some years but would not work when I upgraded my PC. The guys at NASA upgraded the radio to HF3W and supplied the new Meteoscan software and a new interface cable. The resolution is far better than the old software and there are lots more facilities available.On the old setup the output of the radio went to a 9 pin serial plug whereas with the new computer it goes into the microphone socket.
It took me a while to get the setup working because I didn't have the sound card set properly. Once I had that sorted out The results were most impressive.
By the way you tune the radio to the exact frequency of the fax or rtty station and select USB. The beat frequency oscillator is already offset to give the correct results.
Hope this helps.