[VHFcontesting] Log periodics

[Patrick Thomas]

Having seen the topic come up a few times in the last week, I think it's worth reminding that there are numerous books/calculators out there for log-periodics which can enable you to tailor a custom design to any frequency range or gain target or size target that you want, within the limits of physics, and also create something that is highly field-repairable which cannot always be said for factory antennas.  

For roving purposes I like the idea of keeping the simplicity of a single antenna but still handling those unexpected "hey, do you have 220?" moments.  Faster set up, tear down, easier to transport and carry, less coax jumble to worry about, no spacing constraints to worry about (and if they're ignored you loose some EIRP and directionality anyway), etc.  I've been working on a LPDA for myself over the last couple weeks so hopefully we'll see in August whether that effort was worthwhile.

At one point I considered trying to pack a couple common bands onto one yagi boom, as has been attempted by the MFJ 1760 and a couple trapless HF antenna designs.  Not sure if anyone has perfected that approach, but I'd be curious to hear of any promising experiments.

Patrick
KB8DGC