6m DATV Sporadic E

Please post here if you are planning any significant ATV Activity such as DXpeditions or Contest participation
Post Reply
M0DTS
Posts: 653
Joined: Sun Feb 24, 2008 9:03 pm

6m DATV Sporadic E

Post by M0DTS » Mon Jul 04, 2022 5:12 pm

Hi All,

I'm now setup again for DATV on 51.7MHz.
If any European (or uk) stations want to try I can be available for tests.

Tx: Adalm Pluto, 100W DVB-S2 to 5el Yagi
Rx: PGA103 LNA > narrow Band Pass Filter > Ham-it-up converter to 176.7MHz for Minitioune Rx.

I Prefer 125Ks as I have QRM either side of 51.7, but 250Ks maybe possible.

Rob
M0DTS
IO94IL

My Rx Spectrum below, this is after phase/amplitude cancellation of a lot of noise!
The two peaks along with many smaller ones wander about +/-50KHz.
I have to improve the noise gathering antenna a bit yet........
6m Rx M0DTS.jpg
6m Rx M0DTS.jpg (123.28 KiB) Viewed 6368 times





UPDATE!!
An hour later and a better 'noise reference' antenna i have reduced the QRM a lot!
Spectrum vs Rx with 125Ks test signal.
This should be sensitive enough now:

20220704_185654.jpg
20220704_185654.jpg (120.98 KiB) Viewed 6363 times
20220704_185701.jpg
20220704_185701.jpg (191.09 KiB) Viewed 6363 times

pe1itr
Posts: 23
Joined: Tue Jan 21, 2020 10:26 pm

Re: 6m DATV Sporadic E

Post by pe1itr » Mon Jun 05, 2023 9:41 am

It's the month of June. Top of the VHF Es season.

I am QRV on 6m DATV on 51.7 MHz and available for skeds.

Transmitter is DVB-S(2) 30 watts. It's a Portsdown4 with pluto then with filters and amps. The output stage contains 2xMRF300. Receiver is a mini-touner with a series of up and down converters in front of it. Inside the 9 MHz IF is a 400 kHz wide band filter to get rid of unwanted signals.

With Es propagation I will occasionally turn the TX on with a test image and 125 ks. When I'm home the antenna is a dipole for now. There are also a number of wedsdrs active that go up to 52 MHz with which I can monitor the signal.

When "portable" the antenna is a 7 meter long 6el LFA yagi modified for 51.7 MHz. I expect 6m to be a good band for airplane scatter as well. The pad losses are on average 6 ~10 db lower than at 2m.

73 Rob PE1ITR

M0DTS
Posts: 653
Joined: Sun Feb 24, 2008 9:03 pm

Re: 6m DATV Sporadic E

Post by M0DTS » Tue Jun 06, 2023 3:57 pm

Hi Rob,

I'll try to be active after on 6m from home again a few days after the contest, but currently setup for 29MHz.
The path between us is not good for A/S or Tropo and a bit short for Es... but we can try.

I don't think i can fit both 6m and 10m antennas on the mast here!
Luckily my QRM has now gone :-)

I have ~100W to 5el on 6m and ~150W to 3el on 10m.

Another Rob

M0DTS
Posts: 653
Joined: Sun Feb 24, 2008 9:03 pm

Re: 6m DATV Sporadic E

Post by M0DTS » Tue Jun 20, 2023 1:56 pm

I'm QRV on 6m DATV

Default to 125Ks 1/2 DVB-S but I can change as requested.
I'll be on this week after 14:00utc and most of the weekend if you want to try any tests around Europe...
Talkback on dxspot.batc.org.uk or Zello '50MHz Digital Amateur Television' channel.

Rob

g0mjw
Posts: 2330
Joined: Sat Sep 20, 2014 9:15 am

Re: 6m DATV Sporadic E

Post by g0mjw » Tue Jun 20, 2023 2:21 pm

I can also do 6m DATV, if I set it up. I have put 29 MHz back in the box for the moment as conditions have not been so good. Most likely trans-Atlantic two-way will be somewhere like Brazil or Canada as the FCC don't seem to allow anything more than a few kHz wide. South Africa is a good possibility too.

Mike

pe1itr
Posts: 23
Joined: Tue Jan 21, 2020 10:26 pm

Re: 6m DATV Sporadic E

Post by pe1itr » Thu Jul 20, 2023 5:40 pm

I have my DATV station on 51 MHz ready. Made a two-way QSO with ON7MOR as a test last week. It seems to be working all right. On my website I have created a page with the current status of the station: http://pe1itr.com/50mhz/datv-6m-2.htm

On Sunday August 20, 2023 I will be in the DATV contest on 6m/2m QRV from LX (JO30BA). First at 6m and then I convert to 2m.
On Thursday, August 31, 2023 in the evening and on Friday, September 1, 2023 in the morning/evening I will be at 6m QRV from Texel Island (JO23QK).

Zello channel "50MHz Digital Amateur Television" as talkback

73 Rob PE1ITR

Post Reply

Return to “ATV Activity and Contest Discussions”