groovebus

I just tuned my new Firestik 4'. If I remove my hard top do I need to retune it? I'm thinking not since it is top loaded, but it is mounted on the standard spare carrier mount and taking the top off should cut down on reflection. If anyone has experience with issue I'd like to hear it.

Mark Doiron

Don't worry about it. There isn't a bunch of ferrous metal in that top that will affect things. The folks with the softtops have a much bigger issue, and it's just impractical to think about retuning every time you raise and lower the top. Bottom line: Tune the radio for your "normal" configuration, and don't worry about it after that. With so little power, the marginal changes in SWR are very unlikely to damage anything. And, do be aware that even horrendous SWRs still perform okay (provided you don't damage the final amp in the radio). An SWR of 3:1 would result in roughly a 1 db loss in signal. That's virtually unnoticeable to the intended recipient, either in the strength of what he hears, or how far away he hears it. So, while we want to optimize our antenna systems, one shouldn't have much angst over changes as we remove and install tops, load and unload our Jeeps, etc.

groovebus

Thanks for the reply. I didn't think the fiberglass top would cause much of an issue. I've got the swr down to around 1.05 on ch 1 and 40 and less than 1 on 20.

Mark Doiron

It can't be less than 1. You'd have to be creating RF energy from nothing if it really was. Your meter calibration or zeroing may be slightly off. Anyway, sounds like you should be okay.