SWR

I started with an congratulations on your effort. You decided to go somewhere else. Try reading again.

Have fun on your road trip.

 

Glad it looks like it is working.

 

Has anybody tried one of these?

 

Did he say a 27" whip?


Sirio has a small antenna swept back at 45 degrees or so. looked like a typical car FM antenna, i'd put my money on that.

No holes? a mag mount would be better.

 

If a 1/4 mile radius is the only requirement, the glass mount looks kinda cool.

 

It’s what my Dad ended up with during his years with a 1975 all-aluminum travel trailer (a Silver Streak) and his Johnson Mesenger. He could be heard for miles. I used to come in from highway and depend on his directions. Could hail him from 3+ miles.

My later model trailer has the same setup, though it had been removed when I bought it. I now think it may have been a factory installation. And may just buy that and give it a whirl. Thx for posting.

Can’t say as to brand, but it looks as I recall.

 

That’s pretty much a description of the wiring for this RV in that it’s straight from BATT.

While Dads TT was sold a dozen years ago, I’ll check the mount location on mine for strap. It’s likely right against one of the aluminum ribs. Just never thought to check it.

 

Just by changeing coax fixed your issue?? There its hideing another issue elsewhere...Not sure about the ngp system but in others when changeing coax,ya got problems..
Like you were told op,find someone with a antenna analyzer..Swr doesnt tell you much....Basically a good swr is only saying that the radio and ant are happy....Does not mean it works wortha crap for range or efficiency..There are other factors that need to be addressed to get better results..
Other than here have you researched anywhere else for suggestions..

 

Craig, I won't bore you with formulas but a NGP antenna needs a matched length of coax to work.

OK to be a little blunt, I don't get why you all seem to look at an antenna as one element of the system. I mean there are two elements (some call them segments) where the signal travels, it always is two.

In a case of a vertical (just an example), there is always the other half of the signal that uses what is called a ground, which is why in vertical systems there is a counter poise (in fixed locations) or a ground plane in a mobile application (which also has a potential between the vehicle and the earth).

In this case, the antenna (say a 4 ft centerloaded fiberglass whip) is one half of the antenna and the other half using the NGP mount (that's what it is) will need a like amount of surface area to establish the balance between the two elements of the signal. For some odd reason (again not putting in the formulas) adding those three feet did accomplish the balance. The other odd thing that I won't explain is how the coax is using that outer conductor as both a feedline and as part of the antenna but that's what happened.