Wednesday, April 11, 2012

432Mhz HB9CV review

Having used an HB9CV antenna for 70Mhz for a while, I wondered how one of these for 432Mhz would perform while out portable up on the hills. Earlier this year I aquired a 4 element yagi for 144Mhz that is fine for portable use. This left me with a 144mhz HB9CV that I have had for years. I used it occasionally portable and before that used it vertically polarised on my mast at home.
So...what to do with my redundant 144Mhz HB9CV?
Out came my hacksaw along with some measurements and built my own little antenna for 70cms from an old 144Mhz HB9CV!
Looking at this little antenna made me think...will this really work? It tuned well on 432Mhz and during the last contest set it up on a small mast next to my car in the drive. I was quite surprised how I could hear stations that I could hear on my big yagi from the shack. I would have to wait a few weeks for the next contest to try it out proper.
Last night was the Tuesday night activity contest on 432Mhz, so I took my FT817 and HB9CV up to Winter Hill. Setting it up was easy with my window bracket and wooden base. I have to admit that I was amazed at the performance of this little antenna, I could hear stations as far away as the South Coast! I worked a few stations, but I wasn't really interested in the contest, just what I could hear and work long distance.
The HB9CV was remarkably sharp with a couple of side lobes on either side when listening to a distant station and the front to back seemed quite good. The VSWR reads about 1.5 to 1 which is good for a home built antenna!
The problem with 432Mhz antennas is that they are very sharp and we tend to have lots of elements. I used to have an 18 element parabeam, a fine antenna for fixed station and serious contest stuff, but you can miss an awful lot up there on the hills with a multi-element yagi!

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