Transveting to 10ghz DATV

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
Post Reply
G4HTZ
Posts: 249
Joined: Sat Aug 02, 2014 4:21 pm

Transveting to 10ghz DATV

Post by G4HTZ » Thu Apr 20, 2017 8:35 am

Ok ...was wondering if this was practical

I have a DG0VE 10ghz 4w transverter with IF of 70cms ...requires about 100mw of drive at 70cms.

Just wondering if it is feasible to drive it with my portsdown ....proberly with a small amp to 50mw ..would that work
What about RX ...could I use the transverter to the minitoune or require a separation lnb

Be interested to hear from anyone whose done similar .
Essexsteve@icloud.com

Regards
Steve
Steve G4HTZ

ASHEN nr Sudbury JO02GB52 90m ASL

PORTSDOWN and a RYDE …

g8gtz
Posts: 1777
Joined: Wed Apr 07, 2010 6:26 pm

Re: Transverting to 10ghz DATV

Post by g8gtz » Thu Apr 20, 2017 9:19 am

Hi Steve,

Yes - that's exactly what Dave GKQ and I do.

We both have old Mk1 DB6NT and I find I need about 500mw of drive so use a small brick to generate 437 MHz > 10373 MHz with about 5 watts in to my offset dish.

On rx, I go in to my normal 70cms u/c to L band so 10373 = 19636MHz or you could use a Serit to receive 437 directly - you may need a bit more gain at 437 or L band.

Doing this means you can align on Narrow band and then switch to DATV and you've got all the gain / system benefits of the NB system on DATV - we've worked 100+ Km and I tweeted this in March https://twitter.com/G8GTZ/status/840965681290084354

Switching can get very complicated - I'm just re-doing my switch / relay box to try and make it a simple switch throw to change between 70cms and 10 GHz!

We'll be very interested to try from Walbury (or Hoggs Back to start with) to your local high spot (Danbury?) when you get it working....

73

Noel - G8GTZ

G4HTZ
Posts: 249
Joined: Sat Aug 02, 2014 4:21 pm

Re: Transveting to 10ghz DATV

Post by G4HTZ » Thu Apr 20, 2017 9:32 am

Hi Noel
Thanks for quick reply

I have the minitoune with the serit nim ...so presumably could feed transverter RX into serit / minitoune??

If not can use a LNB on a separate dish to feed minitoune.

Just putting together a 1m rfhamdesign dish with about 35db gain at 10ghz.

Local highspot here is about 15miles away which is laindon hills nr Basildon Essex which I think is about 190m asl ...which is 2nd or 3rd high spot for Essex excellent take off to the west
Locator JO01FN02KQ
Regards
Steve
Steve G4HTZ

ASHEN nr Sudbury JO02GB52 90m ASL

PORTSDOWN and a RYDE …

G4HTZ
Posts: 249
Joined: Sat Aug 02, 2014 4:21 pm

Re: Transveting to 10ghz DATV

Post by G4HTZ » Thu Apr 20, 2017 11:03 am

http://www.heywhatsthat.com/bin/profile ... ,-1.477184

Basildon lanngdon hills to Coombe gibbit
Steve G4HTZ

ASHEN nr Sudbury JO02GB52 90m ASL

PORTSDOWN and a RYDE …

g8gtz
Posts: 1777
Joined: Wed Apr 07, 2010 6:26 pm

Re: Transveting to 10ghz DATV

Post by g8gtz » Thu Apr 20, 2017 5:59 pm

Hi Steve,

You can use a separate LNB but then you need a separate dish or c/o system - I'd use the transverter down to 437 but you will probably need a bit of gain (sat line amp ?) before the Serit.

But beware and don't get caught like I did - the DB6NT needs +ve volts on the feeder to put it in to transmit - I use +12v out of my DATV receiver to power the pre-amp and relay when in receive - as soon as I connected the transverter to my rx input it went in to transmit. Took me a while to figure why I wasn't receiving anything! A bit of DC blocking on the input to the line amp will do the trick.

The path looks do-able, so give us a shout when you're ready!

73 Noel
wal to Laindon.JPG
wal to Laindon.JPG (91.47 KiB) Viewed 5504 times

G4HTZ
Posts: 249
Joined: Sat Aug 02, 2014 4:21 pm

Re: Transveting to 10ghz DATV

Post by G4HTZ » Thu Apr 20, 2017 7:25 pm

It will be a few weeks Noel due to holiday and got to get the minitoune sorted out .

I have a inline 70cms lna which is powered via coax on RX and straight through on tx so that's not a problem 0.7 nf about 20db gain ....may need a filter as there is a large communication mast on same site

Regards
Steve
Steve G4HTZ

ASHEN nr Sudbury JO02GB52 90m ASL

PORTSDOWN and a RYDE …

Post Reply

Return to “The Portsdown Digital ATV System”