Image: Location of ZS1COR in George. (Click on image for larger view.)
It is official. The ZS1I 145.550 Mhz Simplex Link on the ZS-Link Network confirmed excellent coverage between George and Mossel Bay. Once again it was the young and new radio amateur from George that again took the "bull by the horns". HERE is the previous article about this active and curious radio amateur living in George.
Image: New Radio Mobile coverage area for George (Click on image for larger view.)
Please Note: The plotting with Radio Mobile is from a fixed base station antenna (X50) to a mobile 5/8 omni-directional antenna. One can expect far better results using two fixed base station antennas which was indeed the case between ZS1COR and ZS1I-L.
Yesterday early evening I heard Corne ZS1COR calling on the ZS-Link Network. I returned his call and this is where it all started. He was literally booming in via the ZS1I 145.550 Mhz Simplex Link. In the past his RF signal was marginal (lots of rain) into the link network. Upon inquiring from him whether he is in the Mossel Bay area, he confirmed that he is working from his QTH (home) in George. I knew he recently acquired a Kenwood TS2000 radio that is able to put out 100 watts on VHF.
Image: Kenwood TS2000 Radio ZS1COR (Click on image for larger view.)
Image: Diamond X200 Antenna (ZS1COR) Click on image for larger view.
Now surely this explain why he was booming into the link from George. I asked Corne whether we could perform a few tests. I asked him to turn the RF Power of the TS2000 down to 50 watts as his audio was over modulating and very loud to harsh. This made no improvement and I asked him to go to 30 watts. He was still booming into the link with fairly distorted audio. He suggested that he would like to do a cross-band test by using his HT on 70cm and then into the TS2000 where after the TS2000 would transmit to the ZS-Link Network. He conducted the test and his audio was excellent but he still romped into the link network. I requested him to do a direct test from the TS2000 with 10 and then 5 Watts of output power. Still very load and rough on the edges. I then asked him to check his RF Gain and the speech processor. He turned the RF gain down to 50% and switched the speech processor off. I need to mention that the TS2000 was new to Corne and that he still has to learn to properly set it up. We once again did a test on 10 watts. His audio was far more better now that the Mic Gain was adjusted and the Speech Processor was turned off. He was still booming in with very loud audio. I advised him to read the manual as I know that you can setup the audio of the TS2000 for you voice and to your liking. I asked Corne to connect the HT directly to his antenna and first try 5 watt and then 2 watt power setting on the HT. His audio was great on the HT and low and behold using 5 watt or 2 watt resulted in a good signal coming from George. On 2 watts a bit of "rain" on his signal was noticeable but this did not effect the contact in any way.
I was really surprised to receive him in Mossel Bay as when we tested the last time with the lower Diamond X50 antenna on the ZS-Link network his signal was full of rain and clearly not as good as last night. What made the difference. Higher power? No as I could hear him very well on 2 Watts from George.
Well the answer lie in the antennas both of us used last night. I was using a Diamond X50 (12 meters) up in the air. This surely made a big difference. With this antenna 12 meters up in the air and with 4.5 db gain proclaimed by the manufacturer this speaks for itself or does it? In a previous posting available HERE I plotted the coverage of the ZS1I 145.550 Mhz Simplex link radio signal with Radio Mobile. This clearly indicate that coverage with the higher antenna in Mossel Bay gives a far better coverage area then the older antenna that was just above roof height. Despite this an antenna at the other side (station) is just as important.
Corne indicated that he is using a Diamond X200 at his QTH with 6 db gain. The Diamond X200 is 8 meters up in the air in George. Moral of the story is that two good antennas between two stations makes all the difference. I have never been able to make a simplex contact on two meters with a George station with two watts using a omni-directional antenna and a HT. Well there is always a first time for everything and Corne ZS1COR proved this last night.
It was great to conduct the tests yesterday evening on Simplex. We had great fun. It took me back many years when there was still great activity on Simplex in this area. Now the above is proof that using good antennas at a decent height makes it possible to easily get into the ZS1I 145.550 Mhz Simplex Link. If you can't get into the ZS-Link network via RF then why not use Echolink ZS1I-L. No excuses anymore in this regard.
Further tests will be conducted over the weekend between ZS1COR and ZS1I (others welcome) and if this materialize I will post and update information in this regard.
Reception and Transmission reports are most welcome and can be provided on the GRHub Network by connecting to Echolink ZS1I-L + AllStar 49355 or via email by clicking HERE.
