Signal Solutions in difficult situations.

13 Apr, 2021, 6:51 AM

Written: November 3, 2017

How does the site of the transmitter contribute to receiving a picture ?

GULGONG

Some great feedback from a customer Mr. Barry Bicheno travelling this vast continent.

He was staying at Gulgong near Mudgee in NSW. In Mudgee there are 2 sets of transmitters located in the hills above Mudgee. They are both directional which means the signal is only pointed in a limited direction. Refer to map. They are both what we call baby transmitters. One is vertical and one is horizontal. They are rated by the ozdigital site as a 2 out of 6 star transmitter which I would agree with. The rating provides an insight into the strength of the transmitters.

Note: How the “H” transmitter looks over Mudgee while the “V transmitter can transmit north up the valley.

Yellow dot is the position of the transmitter in relation to the surrounding countryside. V on dot means signals are vertically transmitted. H on dot means signals are horizontally transmitted.

Gulgong is approximately 33kms away as the “crow flys”. However the signal intended for this area is vertical as you can see on the maps. The transmitter has been located in an entirely different location to maximise the opportunity for the signal to travel up the valley. Also, the ABC and SBS are on different towers to the commercial channels. A caravanners nightmare! It appears the Government have dropped the elevation of the towers in an attempt to get past protruding hills. Their mistake is allocating vertical to this transmitter rather than a horizontal polarity. It would have performed a lot better as horizontal tends to travel further as is less effected by the ground topography.

However the caravanner could search low to the ground for these signals. In my opinion they will be there but they are more likely to bounce along the valley floor than make it through the atmosphere.

Our TV antenna systems including our mounts and masts would allow you to do this.

 

Mt HOPE

The second location he reported on was Mt. Hope. The area is dotted with low output transmitters. There is nothing available in Mt. Hope. My research suggests they are only very low power community funded transmitters in the general area. So I agree with our customer there is nothing available.

 

LAKE CARGELLIGO

The third location is Lake Cargelligo which is in the same general area as Mt. Hope. However there is vertical signals available at Condobolin.

Note: You have 2 broadcast towers which means they will be slightly different in response. This vertical signal will travel across flat farming type land and is appropriately 85kms as the “crow flies”. This signal may be possible to pick up with our caravan antenna. One thing I do not know is what type of soil is in the area. Soil content has a major influence on signal travel. If someone could let me know I will provide a theoretical evaluation. The frequencies being used are ideal but the environment is unlikely to be helpful in getting the signal to you. Therefore your positioning of the antenna has to be laser like.

I would start with something like 700mm above the caravan roof. Antenna on its side for vertical signals and rotate in a north easterly direction. Move antenna no more than 25 degrees to the left and right. Be Patient. You will need your TV pre tuned to do this – if your TV can be pretuned to a specific frequency as some cannot. Leave it on one of the wanted channels and have someone watch it for signs of life. When that happens note your height and exact direction. Now move the antenna up 50mm and check again. Repeat this both up and down until you zero in on the signal.

What the data below tells us:

Affiliation: this is the network the channel is an associate of.

Callsign: This tells you the actual channel number where you will find the signal.

Frequency: This is the frequency assigned to the channel number

Power: This is the output of power from the transmitter

Pattern: Tells you the direction. In this case it is not 360 degrees directed at Mudgee (the town) and another transmits up the valley or highway north.

Polarisation: How is the signal transmitted – Vertical or horizontal.

Mast Site: The physical location of the transmitting tower

You can learn more at https://ozdigitaltv.com/

Sally Garden
RF Consultant Founder
Wilkgard Technology Group P/L