Satellite Antenna build – 70cm antenna

So during a break from studies and the fact this 70cm antenna had been sat in the shack since mid July, I decided this morning to at least make some progress with it.

The warm weather continues here in England/IO90BS – neighbouring Hampshire is now on a hosepipe ban, I’m hoping with the plentiful rivers and springs that Bournemouth will not be subjugated to such things, but with another 30c week forecast next week, who knows. I’m having to do any outside work very early in the morning else its just too hot to work.

wx in IO90BS

I enjoyed my attempts at satellite communcation with the Kenwood THD7 and Arrow antenna, this is great for portable operation. In the shack I have the ICOM 9700, which is built for satellite operation, as yet I’ve only used the 9700 on simplex and repeaters per-band, so probably 50% less than what the radio can actually do ! The Satellite feature allows split channel and (2m&70cm), so I wanted a solution to use the 9700 at the QTH.

I didnt want to spend a fortune on antennas, so I hunted out a reasoniibly priced 2m and 70cm antenna. For today will talk about the 70c antenna, the DUAL PA432-8-1.2RA. I got mine from Nevada Radio, other places sell them, but I’ve never had any problems with Nevada radio in terms of getting products to me and after sales care.

The specifications for the antenna are very good for the price, and with satellite communications you don’t want an antenna that is very focused (i.e. with alot of elements on it) else it makes tracking the passes a very precise movement across the sky. As I’m using an old TV rotator at 30 degrees fixed tinflation, this should be a good antenna for me.

Assembly was easy enough, the instructions and labelling of the elements are very good to ensure they are put in the right way first time. I have yet to threadlock my screws until the antenna goes up, but will do when I know it is working correctly and raised. There is a choke on there, its important *not* to unclips/cut these, if you’ve not seen a 70cm antenna before you might be tempte dto cut them thinking its packaged this way, and its not, just leave as is 🙂

Once completed I erected the antenna on the bike stand. Initial results were disappointing with the SWR very out of the 70cm band. Rembembering how volitle and sensitive equipment is at this frequency I swopped out the coax, which resulted in much better results.

70cm band and the PA432

I was very happy for about an hours work to get an antenna with high gain and good SWR reports.

As I want to mount the antenna on a horizontal beam, I will need to work out how to attach it (probably another 90 degree holder), but for now I’m glad the antenna is out its box and ready to use.

Next week I’ll hopefully get the 2m Yagi built (Diamond A144S5R2) and then can see how to tie it all together.