Larsen FB1136

[joekansas]

I was at an auction at a state facility in Vinita Oklahoma last week and bought the aforementioned antenna, out of a pile of what they were calling junk, for $2.00.

Question here is about adjusting it for certain frequencies. It's end use will be receive and transmit in the 160. to 161. (railroad) range. I have no meter to check SWR. Is there a way to accurately adjust the antenna sans SWR meter, as in measuring the length of the adjustable member with a tape measure, and get it in the ballpark? RG-8 cable to connect it to the radio.

[FLRAILMAN]

Go to: Larsen

Click on: Tecnical reference
Click on: Cut charts
Click on: FB series
And you are good to go.

FLRAILMAN

[joekansas]

Far out! I woulda never found that, nor even thought it would be posted on the web! Thanks!

[joekansas]

Now that I have that chart, I adjusted the lengths of the antenna parts as best I could.

Now, I question if this step is to just get you in the ballpark and you still need the SWR meter to fine tune the antenna because the cut chart is only delineated in 4 mhz steps?

One last question on actual measuring points: This antenna chart gives measurements on 3 different components. Lower rod, phasing rod, and top rod. I understand what those parts are. But, the metal sections of the antenna are basically joined by plastic "ferrules" about 2 or 3 inches in length and electrically joined with a bent wire inserted thru the plastic ferrule. If you are reading this you probably see what I am trying to say!!!.

Whilst measuring distances, do you measure overall length including the plastic parts they fit in, or just the metal tube or rod you are actually adjusting the length of? Common sense would say the chart says the lower rod is to be 36-1/16", so make the rod that length, right? Am I overcomplicating things? I have just a bit of common sense left and don't want to waste it :-Þ