I was contacted by Paul Glover who lives in Worthing West Sussex and is using a…
WeSaCom APT-06 APT receiver
Fed by signals from a…
KX-137 active VHF turnstile antenna
… which as can be seen from the photo above is not mounted on a huge mast with a perfectly clear view of the horizon. This equipment was bought just over a year ago from Wraase Electronics of Altenholz Germany. This setup had been working very well until recently when some images were marred by reduced quality and some narrow herringbone lines running at about a 10 degree angle across and down parts of the image. Paul had tried an uninstall and reinstall of WXtoIMG which he found apparently worked a few times but then no longer had any effect.
I was unable to offer any concrete suggestions beyond some local noise source but doubted the fault lay with WXtoIMG.
Paul got back to me to say he had isolated the problem to the soundcard and was temporarily using an alternate PC. He has been kind enough to offer his latest images for use on DigitalHam. They show just what can be achieved when there is no pager interference. Quite apart from that though they show virtually no low elevation noise (top and bottom of image clear) so obviously his antenna and radio are working better than mine too – I suspect that the masthead preamp in the KX-137 must take much of the credit here. Given the pager noise I won’t be making alterations to my own setup until I have more time on my hands when I’ll initially have a go at making a notch filter to zap that pesky pager tower.
Click the thumbnails to see the full sized image.
I’ve had a fair amount of correspondence with Paul and now DigitalHam is running WordPress I’ve added much of it as Comments to this page.
Now for someone with the same receiver who suffers noise problems…..
Colin Osbourn has emailed me this sample image from a NOAA15 pass. I think some noise could be from a pager tower but probably not all. Certainly there is some general noise towards the bottom of the image which is probably due either to an obstruction or possibly a relative null in the antenna response. Using the PDW pager decoder software would give an idea if pager noise is present. I found getting the volume level correct is quite tricky though and nothing will get translated unless this setting is correct.
Colin’s latest image after lowering his QFH as discussed in the comments below and this follow up email…
Following up from the comments that I posted on your website today, I’ve enclosed an attachment showing how much better the images are.
The story behind it was that I was talking to Iain (M1OOO) at the Norman Lockyer Observatory, and he mentioned that they had to take down their QFH because of the recent high winds. It was up at about 30ft, they lay it down at the base of a hedge and left it there. A while later they tried to see if they could get any response from it, lo and behold, great images and not that much difference in quality! So, I thought that I would give it a try, not laying it on it’s side, but just lowering it. And it worked. But, like I said on your site, the foil insulation in the shed was a big part of it.
Anyway, I hope this may be of use to someone else.
all the best, Colin. 2W0OZY