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GB3HV status

Visit 29th March 2017

GB3HV status Posted on Thu, March 30, 2017 16:52:50

Replaced fancy new card reader 1 year old with 10 year old Sandisk reader and it just works 🙂

Replaced Arduino on rotator control again – think problem is spikes on voltage input from actual rotator at top of mast – put some buffering and decoupling but may be lightening induced? Have to see….

Fixed the RB-TV auto select – replaced 567 circuit with a simple transistor circuit to switch on the 22 KHz from MiniTiouner when signal present.

I wonder how long this will all work for?

Delivered the 23cms aerial auto switch system to Mike G8LES so he can build a standalone tray….

Visit 21st march

GB3HV status Posted on Thu, March 30, 2017 16:48:05

Quick visit to check out rotator and card reader – didn’t mend either 🙁

Visit 24th Jan

GB3HV status Posted on Tue, January 24, 2017 16:56:19

Quick visit today – replaced the actual Arduino in the rotator controller and it now works:-)

Also replaced the 10GHz oscillator on the web SDR so it no longer drifts with temperature.

Maybe the complete rebuild can wait for warmer weather 🙂

Visit 4th Jan 2017

GB3HV status Posted on Thu, January 05, 2017 09:28:06

Not a good day yesterday 🙁 Primary tasks were:

Sort rotator out – failed, looks like an Arduino problem.

Sort 23cms interference – at least we know now it is a signal on the North aerial on 1242MHz. But lost for solutions at moment – and the mast head pre-amp box screws are ceased up.

Sort media / picture card reader – failed, buy new or replace capacitors.

Sort BH link audio – failed, looks like a rxr problem.

Sort RB-TV auto switch over
– failed, looks like detector circuit has died. Back on DTMF 775

Replace SDR 10 GHz LNB with locked version
– done but still drifts!

In view of the above and the current rack arrangements we have decided to do a rebuild in to a 5ft rack which I have available – likely to be started in 2 weeks time.

During the rebuild we will sort out the above problems, implement RB-TV switching, automatic BH linking and look at potential of integrating the original HV 23cms aerial switching system. Likely to be off air for a week….

But it’s still on air now so keep using it 🙂

437MHz RB-TV

GB3HV status Posted on Thu, October 27, 2016 19:00:26

Visit today saw the 437 MHz 333Ks RB-TV input configured such that it is now automatically selected.

Transmit on 437MHz RB-TV and initially it will display a caption saying 437 MHz RB-TV input then after a few seconds (the Rpi decode time) the incoming video will be displayed.

Replaced the card reader power supply so we now have pictures back in beacon mode again.

**** I’ve just realised the DTMF codes in both the video selection and aerial selection captions are WRONG – see previous blog for aerial codes or refer to the user guide for correct codes ****

Also tried to resolve the mystery 23cms input signal on the north aerials by moving the 70cms yagi but it no effect so we still have the problem occasionally.

Yet more power issues

GB3HV status Posted on Tue, August 30, 2016 14:07:58

Back again today – looks like we had some more power issues on site as both the Netiom control card and the picture card reader needed reformatting / reprogamming and the 70cms DATV rxr PSU had to be replaced!

All is well again….

437 RB-TV input and rotator update

GB3HV status Posted on Sun, August 28, 2016 09:20:31

Visit on 27th August:

Rotator update (again)

A brand new rotator has now been fitted and is accessable at – a 6 ele yagi for 70cms 437 MHz and the mast camera are mounted on the mast.

The camera can be selected by DTMF 776 on the 432.750 control channel or via Skype – see user guide for full instructions:

RB-TV input

The PC was also upgraded enabling us to run Minituner which has been set to receive 437 MHz 333Ks (this can be changed remotely by request). This works in parallel to the normal 70cms DATV receiver and is connected to the 6 ele yagi. The Tutuione monitor can be seen at the bottom of the rotator control page and on the VivaDATV page at

The UDP output from Minituner is streamed to a RPi which currently feeds composite video in to the logic input selected by 775. There is about a 5 second delay on the video and when no signal is received a caption is displayed. DX stations who can see their signal on the TT monitor will either need to use Skype (you need to be pre-authorised) or put up a message in the chat window requesting a local user selects DTMF 775.

Work is ongoing on the RPI software to automatically detect when a signal is present and when this is done, the RB-TV input will be automatically selected – just like the 70 and 23cms inputs.

23cms antennaes

The 23cms flat panel system was physically inspected and confirmed the following DTMF selection codes:

Note – these were wrong in the original post on 27th Aug (joys of cut and paste) but have been updated on 29th Aug and are NOW correct:

DTMF Function
*50# Cancels all selected aerials
*51# Selects West aerial
*52# Cancels West aerial
*53# Selects South aerial
*54# Cancels South aerial
*55# Selects East aerial
*56# Cancels East aerial
*57# Selects North aerial
*58# Cancels North aerial

For example, the best selection for these stations is as follows:

G8DGR = NNW = *51# PLUS *57#
G8GTZ = WNW = *53#
G8CKN = SW = *53#

Power reset!

Having done all this and installed the air con unit, the site suffered a major power cut last night and the PC did not restart!

This meant an early morning trip on Sunday to site just to restart it (normally the UPS would hold it on but the power cut lasted 6 hours….)

General update

GB3HV status Posted on Wed, August 24, 2016 08:35:21

Notes from site visit on hottest day of the air (23rd August 2016):

1 – 70cms filter and pre-amp moved to top of mast gave 2-3 dB increase in sensitivity.

2 – Fitted replacement rotator and cable. Whilst this one does go round (the old one had stopped) the direction indicator, which worked fine for 2 weeks at home, is now short to earth! I can move the rotator via an admin webpage but cannot make that publicly available, as going to the end stops will short out the 5volt railsmiley The rotator is currently back in the original position but if you need it turning, let me know.

Tests with G8ADM at 56Km with the new rx system and the beam pointing at him, showed he could access HV with less than 100 milliwatts so plans are already in place to buy a completely new unit.

3 – Skype video fixed by replacing the 5v PSU on the VGA to PAL converter.

4 – Balanced up the audio channels on the output so you can now hear 144.750!

5 – The 23cms rx aerial system continues to be a bit of a mystery and despite no work being carried out, the south aerial (well the one invoked by *57#) seems to be taking off and holding the squelch open.

Everything else works well but it’s very annoying to monitor – if you can access via DTMF, try using *51# to select the west aerial which quietens it down for 30 minutes .

6 – Martin, G8JNJ, was with me and did a lot of work on the co-sited web SDR He made great improvements on the 50 MHz receiver – and its always useful to monitor the SDR to see how strong you are on .750 and 432.750.

We will return soon with the new rotator….

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