Hints on using FLDigi for HF wefax?

[N1EYZ]

Folks --

I have a RSP1A that is attached to an antenna tuner and then a long wire. I'm noticing a lot of variability on receiving HF WEFAX from NMC on 8681.0 and 4345.0. (I'm in Oregon, so the signal is coming up the coast from Pt. Reyes, CA.) It may be band conditions or local noise, or the fact that I don't have a ground hooked up. The symptoms are often lack of consistent line sync. The help on the internet is not super helpful and implies that the lack of sync can be corrected off-line -- I have no idea how that is done.

Once in a while when the signal is really strong, I'll get a good image. More often than not, I get something that looks like the attached.

Any thoughts are helpful, especially from experienced FLDigi users.

Thanks,
Roger (N1EYZ)

[Mike2459]

Try Lock Output Fractional Resampler in the RX settings windows in SDRUno. This usually helps straighten out the image. Then use fldigi's slant adjustment to remove slant.

LOFR.JPG (36.74 KiB) Viewed 17464 times

[N1EYZ]

Thanks -- I'll try that!

[jorgesantos]

Your wefax image seems to be the result of several problems, not just slant, namely time sync/accuracy (of your pc sound card )and horizontal shift (your image is reversed in the XX coordinate with a blank strip in the middle)

Suggestions:
- read the Fldigi manual - the section on wefax is very detailled and informative
- there is a routine built in Fldigi to check timing issues (WWV signal)
- check if the small diamond at the lower right corner is green - a common mistake with digital modes is overloading
- check horizontal adjustment

Hope this helps.

bw
Jorge

[N1EYZ]

Thanks for this additional info!