Until end of sunday the 15th dec AARL 10m contest…
Here a screenshot of a part of the 10m band at my location.
Author Archives: mario
Some antennas on a watertower…
Marconi Memorial Contest 2013
We did not have enough operators for a DM7A operation from uphill. I did not want to skip the contest completely and therefore i did the Marconi Memorial 2013 for 6 hours on sunday from Triebenberg JO61XA. The setup was somewhat unsual. I used a portabel setup consisting of my FT-857D and a HL-200V/50 and a 11ele Tonna. I had to power the station from my 1kW gererator.
Before i was a bit sceptical about the capabilities of the setup because the FT-857D is definitively not made for VHF contest operation. But since i have a narrow CW filter and the station densitiy was quite low i was lucky and faced absolutely no overdrive of the RX and almost no QRM by closeby stations.
In the end i had a total of 120QSO with about 36500 points.
One of the first qso was the ODX with IK5ZWU/6 who had a surprisingly strong signal for about 830km distance. MNI TNX Walter !
How the things develop …
Impressions from CQ-WW-SSB
KBS from Sofia in DRM/AM Simulcast
The korean national service KBS is currently testing DRM-AM simulcast. This means the same service is transmitted side by side on co channels. One channel contains the service broadcasted in DRM mode, the next channel contains the same service via AM. This gives the opportunity for some nice comparisons between DRM and AM stability and audio quality. Find two audio snippeds below.
The transmissions will be every evening from 19UTC to 20UTC on 5875kHz (DRM) and 5885kHz (AM) – source www.drm.org
The screenshot shows a part of the radio band yesterday evening. Unfortunately the conditions to Sofia had been really poor. You can see the both signals of KBS and some much stronger signals from other broadcasters.
Obviously the DRM signal was suffering from sideband lobes falling into the DRM spectrum limiting the SNR because at the end when the modulation was already switched off the DRM SNR increased rapidly.
Voice audio snipped – first DRM, then switching to AM
Music audio snipped – first DRM, then switching to AM
The DRM audio was transmitted in AAC+ Mono with 18kBit/s. It gives a rather nice sound compared to other DRM broadcasts that can be received at the moment.
DUR activity 2013 October
After 2 month of inactivity from my side another trial with 3 bands. I had 23/13/9cm with my 1.5m dish.
Meanwhile i integrated the 5W PA for 9cm. This time Murphy tried to do its very best.
I had to tear down the antenna 3 times in between. First i had troubles to find the correct lengths of the ropes for the mast.
When testing the transverters i experienced 9cm was not switching to TX. During my mast trouble i accidently disconnected the 9cm power cable at the mast unit.
After that operation was going relatively smooth. This time i was heard very well by the others on 9cm. But i experienced that my RX seems to be really poor. I always gave much better reports than i got. I did not check the sensitivity so far. Everything you dont check will not work ;)
In the end i had 17 QSO on 23cm, 9 QSO on 13cm, 5 QSO on 9cm.
ODX on 23cm was HA5UA/p. Thanks for the patience during that weak signal QSO.
Next steps with improving my setup will be a new rotator control. The original KR600 controler has some issues and i somethimes do not get correct heading. 23cm would need to be mounted to the mast. Unfortunately i dont think that i can get the mast up then. It would be too heavy.
Back with new URL…
The blog was off for some days because of vacation. After returning i noticed that dyndns completely discontinued the free service even for old accounts and since i did not want to pay 25$ to go back to ath.cx i decided to move to no-ip. Now the new URL will stay dh5ym.hopto.org as long as possible.












