Showing posts with label 27 MHz. Show all posts
Showing posts with label 27 MHz. Show all posts

Friday, January 13, 2017

Slim Jim Vertical Half-Wave for 27 MHz & 28 MHz

Another one from an old magazine article. This design is for a basic folded half-wave vertical for the 11m CB band on 27MHz but it can also be adapted very easily for 28Mhz or 29Mhz. For 10m operation, try reducing the half wave section to 5.10 metres and the quarter wave section to 2.53 metres.



It really is a case of experimenting and see how you get on. It's likely the biggest challenge will be the mechanical construction rather than adjusting the VSWR.

One particular advantage of this antenna is that the quarter wave tuning section effectively puts the radiating element higher above ground level. This fact alone can have a significant effect on the performance of the antenna as it begins to get clear of buildings, electricity wires and other clutter near ground level.

A lot of novice CBer's get fixated on 'advertised gain' and different types of antennas whereas they should be concentrating on getting a decent antenna up as high as possible.

While the Slim Jim won't be as good as say a Yagi beam up on a tower, it should still perform pretty well.

Sunday, November 6, 2016

CB Divisions on 27 MHz

It can often be useful to listen on the 27 MHz CB band to see if propagation is likely on 28 MHz, especially when the 10 metre band seems dead. The fact that it is slightly lower in frequency can mean that the CB band will open before 10 metres for F2 and Sp-E propagation.

Many of those CB operators who are into DX-ing use 'Division' numbers. For example, if you heard '26 AB 123' then that person would be from England.

The full list is shown below.