HI Bernie Thanks for the comments....
Things have improved a bit with the PSK efforts. I found the speech processor was 'on' on the rig - and turned that off! Also turned down the drive a little to the rig, and lifted one of the cable sceens between PC and rig... Had a couple of european qso's last night - got signal reports of 599 as well <grin>! - so can't be all bad..... As far as Isolation goes, I did the sums and decided I might as well get the complete kit from the India amateur (further down the thread) - as the local price of the two transformers was going to be about the same as the cost of the whole kit supplied by him - so I'll go fully isolated once that arrives.... Many thanks to all for their input - see you on PSK ! Adrian EI5JV --- In [email protected], "ve3fwf" <[EMAIL PROTECTED]> wrote: > > My experience in running digital (since 2002) is that RF can creep into the computer and that can cause some nasty issues. I finally fixed my problem by purchasing a properly shielded computer (a older Dell GX1). I use a home brew OPTO isolated interface from the computer to the PTT of the radio; very easy to make. Many computers today, especially clones, are not RF tight. There is some conductive paint that you can apply inside the plastic covers. If you are hearing RF trash from your computer on your receiver you can be pretty sure it may be susceptible to interference as well. Getting rid of the CRT monitor also helped eliminate any RFI from the computer. > > Try some ferrite beads on the audio lines and the mic input; that might do the trick but I suggest the 1:1 transformer is the best bet. > > 73, Bernie, Ottawa, Canada > > > ----- Original Message ----- > From: Dan Reed > To: [email protected] ; [email protected] > Sent: Wednesday, January 03, 2007 11:11 AM > Subject: Re: [digitalradio] New to PSK31 - advice please ?? > > > > Radio Shack some times ha isolation transformers > N0ZIZ > > > > -----Original Message----- > From: adrianrav4 > Sent: Jan 2, 2007 4:10 PM > To: [email protected] > Subject: [digitalradio] New to PSK31 - advice please ?? > > > Hi All > Having just moved house (& country!), and set up the HF radio gear for > the first time in quite a few years - I'm having a dabble with PSK31. > > I suspect that I'm having problems with poor isolation between the > radio and the PC - at the moment the 'quickly knocked-up' interface is > 'direct' - no opto or transformer isolation. > I can read the PSK31 quite nicely (using DigiPan) - and load up the TX > on low power (10W) - but higher TX power seems to generate odd squeaks > and general instability.... > ...also - I have yet to get a reply from any other station on PSK - > which makes me wonder if my signal's getting distorted past the point > of readability ? > > Does anybody have a source for 1:1 audio isolation transformers ? I > can't seem to find them from the usual suspects (ebay, CPC...?) - > would need to be an organisation that ships to Ireland..... > > Many thanks in advance > Adrian - EI5JV >
