VHF Antenna differences?

Doryman · Posted: Thu Aug 30, 2007 10:53 am Post subject: VHF Antenna differences?

Someone recently commented, in passing, about the importance of a "good" antenna for the VHF. I believe I have your basic garden-variety Shakespeare antenna (will have to check) but I would appreciate more info on this topic.

Thanks,
Warren

rogerbum · Posted: Thu Aug 30, 2007 11:06 am Post subject:

My sense is that the "garden variety" 8' Shakespeare antenna is plenty good (especially around here) for the most important use - e.g. contacting the coast guard. Any place in western WA, the CG has so many large antennas sprinkled around that they can hear you on even the crappiest of radio/antenna combos. They also have very high power transmitters and you can hear them on a similar set up. However for ship-to-ship communication (or open water, off shore communications, or in other areas of the world/country), the quality of the antenna probably matters a lot more. I think the most important thing though is still height above the water which is what will limit the range most often.

Thataway Bob has a lot more experience than most in this regard (actually in many regards) so perhaps he can chime in.

thataway · Posted: Thu Aug 30, 2007 6:56 pm Post subject:

We have done a fair amount of testing with our ham radio gear on the various antennas, plus some "practical" testing. I tend to favor the Digital 8' series with a soldered on PL259 fitting. There are some good studies which show that the easier "press/clamp on 259's do not give as good performance as a good solder job. This was brought home with several boats which all had the same AIS recievers. One boat was getting signals at 25 miles, the others were at about 12 to 14 miles. The only difference was that the better reception was a well soldered connector vs the screw on clamp on cheaper connectors. The mini connectors of the Digitals are not quite as good as the properly soldered on PL 259's. I found that the SWR of the Digitals were more likely to be close, than the Shakespeare. I take an antenna analyzer with me to the store when I buy an antenna, and have found some antennas which were quite a way off. Go with the best quality of exterior paint--some of the cheaper fiberglass antennas, get "fuzzy" in a few years.

I also prefer a good SS mount to the plastic mounts. (I have to replace the plastic mounts on the CD 25--it has become warn and sloppy.).

I have a top of the line Shakespeare and Digital on the Tom Cat, both are driven by almost identical radios, and I always seem to get both better reception and transmission on the Digital. But just my opinion...After all, these are just a piece of wire--some with tuned stubs. But a poor installation job can negate a good antenna.

matt_unique · Posted: Wed Jan 02, 2008 11:45 am Post subject: Digital vs. Shakespeare

What model Digital are you using on your Tomcat? What model Shakespeare? Also, do you have to buy a special PL259 connector to solder or did you somehow solder on the twist on type?

Thanks

Doryman · Posted: Wed Jan 02, 2008 2:14 pm Post subject:

I have an Icom M504. It was installed for me so I don't have the particulars on the antenna or the installation -- sorry!

Warren

thataway · Posted: Wed Jan 02, 2008 9:34 pm Post subject:

The crimp on PL 259 connectors cannot be soldered. Any good radio supply shop will have the soldered connectors. You need a fairly high wattage iron to get the connector hot enough to melt the solder properly.

I have the Shakespeare 5225XT 8 foot VHF antenna and the Digital 529 VW VHF antenna. I run two Standard Horizon radios--althought they are not identical, the specs are similar (one is the black box, with ram mike, the other is the combo hailer, VHF radio).