ATV DX

[VK3AKC]

The above words do not exist in the Digital World but do in the Analog World.
Are there any ATVers out there interested in trying some Simplex Analog ATV DX on 70cm of course in a non interference mode with VK3RTV.
I am living in an area where it is impossible to receive VK3RTV (Diamond Creek)but would possible be able to force some Analog signals through.
Surely there are some old timers who still have their 70cm ATV Transmitters in back cupboards growing cobwebs who would like to try some weak signal or strong pictures around Melbourne. I (VK3AKC formally VK3ZVJ), used to live in Preston and was a very active ATVer and sent and received pictures in the 1970's all around Melbourne and even P5 signals to VK7EM in Penguin.
Now living in Diamond Creek even with a 88 element J Beam not a sausage from Vk3RTV. Even though all commercial dtv services are solid.

Before some of you Digital purists jump all over me I find that looking for Analog Atv signals through raging snow storms would be more interesting than watching a solid picture switching on and off perching on a cliff face.
The BATC signal is O.K. to see if there is a signal but the quality is so bad that it hurts the eyes after trying to watch it for a while and it is hit or miss if you can get audio that you can listen to. Also the delay is such that you can make a cup of coffee between a question and an answer. The Utube relay during the ATV Party was perfect and full marks to the organiser. The only problem was the amount of download data usage it used.
This is getting off the subject anyone want to play Simplex Analog Atv?

Kevin Callaghan
VK3AKC (formally VK3ZVJ in the 1970 ATV days)

[VK3LL]

Hi Kevin,

By plotting a path from your QTH (as per the ACMA database) to VK3RTV in Olinda, I see that you are blocked by the summit of Mt Dandenong, so no wonder you cannot "see" the ATV repeater directly from your home.

Path from VK3RTV (Left) to VK3AKC (Right)

I seem to recall that Peter VK3BFG still has some analog (426.250MHz) ATV Simplex capability and I think several others as well - might be worth in on calling on 147.400MHz (ATV Liason freq) from time to time to see if anyone takes up the challenge. In addition, I'll spread the word around my contacts as well.

Since moving to Digital a few years ago, I regret that I didn't keep any of my old analog (VSB) ATV transmitters from when I was playing around back in the 70's as well (as VK3ZIP).

Warmest regards,
Ralph VK3LL

[VK2KRR]

You can still get Digital TV DX, you just have to be on air at the right times. Admittedly, it is quite difficult, although pretty exciting to see it happening.

Below is 44 Adelaide coming in here @ 760 km. On 543.500 MHz.



Also some pics of some Port Pirie DTV coming in around 860 km. Pretty sure Port Pirie TX is in the 700 MHz region.

Port Pirie DTV 1

Port Pirie DTV 2

[VK3AKC]

Congratulations Leigh,

That is some effort. Did you watch the spectrum thru an analyzer for signals to pop out of the noise or using the weather patterns plot and hope.
What is the Vk3RTV record ,Peter?
Would luv to use 426.25Mhz Ralph but unfortunately... Can still transmit both 70 cm channels
would be interesting to see more ATV on 70cm with good antennae next to no interference should be possible as was in the analog simplex days.

Food for thought
Kevin VK3AKC

[VK3LL]

would be interesting to see more ATV on 70cm

Yes Kevin, I agree it would be nice. But I think the big issue is that in order to comply with todays 70cm band plan, ATV Simplex has to be done on 444.250MHz using VSB with several MHz of bandwidth. With the VK3RTV repeater output largely occupying the same bandwidth allocation - RTV would clobber the picture. For this reason, most ATV (around Melbourne at least) is now transmitted on 23cm, as that is also the input to the repeater.

Cheers,
Ralph

[VK3AKC]

Sorry to disagree Ralph but with VK3RTV having an ERP only in the region of watts certainly not hundreds of watts I think the shoe would be on the other foot.Directional beams with some gain would wipe out any sign of VK3RTV. Digital TV is a very fragile transmission mode. Not that I am advocating trying or suggest anybody else try.
We must all work in harmony.
As for ATV on 23cm and above my personal opinion is that it is a most useless project and suitable only for fixed point to point communications (links) try finding a signal without knowing it is there and pointing directly at you with a multi gain antenna. 23cm and above is not of any use to the old time ham looking for DX and working many stations. It is for the experimenter and the rag chewer who wants a private spot to chat with no interruptions.(Boy will this cause some reaction)
I apologize for getting off subject . I enjoy stirring sometimes.
Regards to all
Kevin VK3AKC

[VK3LL]

Hi Kevin,

having an ERP only in the region of watts

VK3RTV was upgraded last year - I think it runs 120W now, albeit with low gain antenna. But of course you are correct - directional antennas do allow the allocation to be reused multiple times across a wide geographic area.

ATV on 23cm and above my personal opinion is that it is a most useless project

The point I was making here is this is what most of the current Melb ATV users have at their disposal right now. Since the VK3RTV repeater went to 23cm input and 70cm output, there aren't too many left with 70cm simplex gear - which of course brings us back neatly to your original point. My investigations reveal that David VK3JDA and Peter VK3BFG may still have some 70cm ATV gear, although probably FM and not VSB.

23cm and above is not of any use to the old time ham looking for DX and working many stations

Yes, that should spark some comments amongst the VHF/UHF Field Day fraternity who relish in DX on the higher bands .

Cheers,
Ralph VK3LL