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Focus on VHF and Above 20 January 2019

Last week we spoke about the VHF bands. This week we are going to look at the UHF bands.

The first UHF band is the 70cm band from 430 MHz to 440 MHz.

This is a fairly large band that has been allocated for amateur use. A whole 10 MHz. Looking at the band plan there are all the usual repeater, MGM, Telegraphy, SSB and FM allocations, but then there are a couple of interesting allocations as well. The first one is an APRS frequency at 432.500 MHz. APRS has traditionally been on 144.800 MHz.

There is also an ISM / Licence Free short range radio allocation right in the middle of the amateur band from 433.050 MHz to 434.790 MHz. There is also provision made for Digital Voice channels.

The next band is the 23 cm band from 1240 MHz to 1300 MHz.

This band is a whole 60 MHz wide. Lots of place to play radio and only a small portion of the band is currently actively being used for long distance communications. Again all the usual allocations on this band, however there is provision made at the top of the band for 5 high speed digital data channels, each 150 kHz wide. Equipment to operate on these bands tend to be expensive, meaning only a small group are active here in South Africa on this band.

The 70cm and 23 cm bands are the only bands that you will find in the normal off the shelf amateur radios, sometimes the bands will be standard or they may be an option that you would need to purchase. From here on up you would need to use your ingenuity and homebrew your own equipment. While it is a lot more challenging, it is not impossible. Let us look at the next band.

The 13 cm band covers the frequencies from 2300 MHz to 2450 MHz.

Now equipment becomes challenging, but do not despair. Your 2.4 GHz wireless router channel 1 has a frequency of 2412 MHz and channel 8 a frequency of 2447 MHz. At what frequency does a microwave oven’s magnetron operate? Around 2.45 GHz. Take a look at the article at https://n5dux.com/ham/files/pdf/High Power Magnetron Transmitter.pdf

Now that should get you thinking.

Then we have the 5 cm band from 5650 MHz to 5850 MHz. Guess what frequencies the 5 GHz wireless routers operate on. Channel 132 is on 5660 MHz and channel 169 is 5845 MHz.

Next up is the 3 cm band from 10000 MHz to 10500 MHz. Both Hannes ZS6BZP and Cor ZS6CR have demonstrated that you can easily generate a signal at these frequencies. Hannes did it at an AMSAT SA conference and Cor did it at the last VHF Workshop. This is why you need to attend these workshops and conferences so that you can broaden your knowledge and expertise.

I look forward to seeing you at the next VHF/UHF/Microwave workshop at the National Amateur Radio Centre on Saturday 9 February 2019. Go to http://www.amsatsa.org.za/VHFUHF.htm and complete the booking form. The cost is only R50 for SARL and AMSAT SA members. Come and listen to the interesting presentations focused on the VHF and above bands.

Let us now have a look at some news about the VHF and Above bands...

Here is again some news posted by Pieter V51PJ.

Pieter did some test over the last weekend on 6m and found it interesting that the Meteor Scatter came in bundles, then disappeared for a while and then came back again. This was also experienced by Tom ZS1TA and Andrew ZS2PA, who persevering with Meteor Scatter took close to an hour before managing to log a call successfully. This was due to the Meteor Scatter bursts being very sporadic.

Pieter also noted that there was an Aurora alert this past weekend and was wondering what the effect of this solar wind would be on the Meteors. Would it boost Meteor Scatter activity or not?

Pieter hopes to make contact with many of you during the Pears VHF/UHF contest this weekend.

Well that is all the VHF and Above news for this week.

Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.

What about the new hams out there? I’m sure you have lots of questions and don’t know where to find the answer. Send us your questions, and we will provide the answers in the form of a tutorial that will not only benefit you, but your fellow radio amateurs as well.