G8MNY > DIGTV 15.08.18 10:30l 81 Lines 3458 Bytes #9 (0) @ EU
BID : 33625_GB7CIP
Subj: Digital TV /P
Sent: 180815/0829Z @:GB7CIP.#32.GBR.EURO #:33625 [Caterham Surrey GBR]
To : DIGTV@EU
By G8MNY (Updated Feb 07)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
Here is my experience of /P DTV. I have had mixed success with this.
MY /P SYSTEM
I have a small 12V Freeview STB by Panasonic, & I feed the PAL video from it
into a 7" Widescreen DVD player (Duff player) which is ideal as it is matching
in size, although limited to 3MHz (300 line resolution) is the best the player
will actually display although anything on a small screen looks really sharp.
Set top Aerial
,|││││ short ┌─────────┐ Video │ Widescreen │
├┼┼┼┼┼┤───────────┤Panasonic├───────┤ Sharp L70S ├─────>Earpiece
'|││││ coax ┌─┤ TV-CT20 ├───────┤-----DVD----├─┐
'|│ 12V│ └─────────┘ AF └────────────┘ │12V
On │  Remote │(9v)
Ladder rack PSU Control PSU
The aerial can be mounted either H or V polarization in it's set top support
bracket on top of my van latter rack for /P.
It is a very useful set up for seeing if there is usable Freeview TV possible
at different locations as well as /P operation.
I have tried it for /P operation (camping in my Van) @ 3 sites where I had
plenty of time to sort out all the Rx options.
One location was at VHF Contest site 280M high @ Woldingham in Surrey, it is
line of site to the main Crystal Palace QRO analogue & QRP digital Tx 15km
away. Although the DTV signals are weak at that distance for the small aerial
mostly all the signals were OK, but early morning I tended to loose all the
signals in tropo where the signal is no where near the ground!
_ - ~
300m _ - ~ Lifted RF Beam /P
ASL \│/ - ~ _ - ~ ~ ~ ~-_
│ _ _ - ~ 280m ASL ~-_
100m │ _ - - ~ ~ Hill near
/ \ _ _ _ _ _ _ - - - - ~
Crystal Palace Woldingham
The 2nd location was Shilton in Oxfordshire, where only some channels could be
found from 1 Tx, the obvious TV Tx in Oxford was not usable /P, but was fine in
a local cottage in the valley on proper aerial Rx all the stations OK.
The 3rd /P location was @ Reigate hill in Surrey just inside the M25, very near
(1km) to the Reigate analogue & digital TV repeater. It gave only a few
channels & attenuators did not help.
| Crystal * |
| Palace |
| W'ham |
\ C'ham * /
M25 `\ /P /'
`" -- ... ___ ... -- "'
Crystal Palace QRP Tx was line of sight, but too far really for that small
aerial with weak digital signals, so again only a few channels worked. But I
did unexpectedly find another repeater in the Caterham direction (I did not
know it was digital) that was OK with all the channels.
Playing around with digital /P is not like analogue, as it does take a lot
longer to find a usable signal with all the STB scanning & beaming up etc. &
not always from the obvious Tx source!
Y don't U send an interesting bul?
73 De John G8MNY @ GB7CIP
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