Center frequency 27.185 +/- 00 670.
Press button “3” and you can get center frequency and arrow down to enter the range.
First off keep in mind, channel 19 is 27.185 MHz, Low 19 is 26.735 MHz as a reference point.
Band C Band D Band E
(Low side) (Normal) (High Side)
26.515 26.965 26.415
26.735 27.185 27.635
26.955 27.405 27.855
Take the Highest frequency minus the lowest frequency of Band E to C, divided in half
27.855 – 26.515 = 1.34 MHz (120 channels).
1.34/2 = 670 kHz (670 kHz enter its as 00 670 on the analyzer
So my center ω is 27.185 (channel 19) and I’m scanning 670 kHz on each side.
This is a scan of the low side of channel 1 to the high side of channel 40, 120 channels.
The acceptable bandwidth (BW) of an antenna is based on the 2:1 plot and most trucker antennas BW is fairly narrow. As you go to a shorter antenna length, say a 4’ going to a 3’, etc (adding tons of inductance) and the BW narrows exponentially. A 2’ might not even tune 1 through 40 and forget about a 1-footer.
My low side tune:
27.405 – 26.965 = 450 kHz BW for the normal 40s or any bank of channels (A-E).
Channel 40 minus Channel 1 = 450 kHz
Channel 19: 27.185
Low 19: 26.735
27.185 – 26.735 = 450 kHz/2 = 225kHz. 26.735 + 0.225 = 26.960, channel 1 is 26.965, close enough.
Channel 19 minus low side 19 divided in half will give you a center frequency of 26.965 (channel 1).
Now I do a low side tune IF that’s where the guy is mostly talking and will still get him good VSWRs on regular 19. Low 19 is now equivalent to channel 1normal, and normal 19 is equivalent to channel 40.
It could be a problem if the antenna doesn’t have the BW and if he has to talk on say channel 40 (27.405).
If you go to scale houses that operate on channel 36 -40, some truck antennas will have a problem going from the low side of 19 to regular 40, It’s just not built into the antenna. Kinda like getting blood from a stone.
A Stryker SR2K usually does, but that is dependent on the other end of the antenna, the truck (ground).
If you think your secret channel is lower than band C or higher that band E, any of my Stryker’s will shut down and say “HIGH SWR”.I’m working on getting into the software to say,”ASSHOLE” or maybe “FUCK OFF” but they won’t let me. But I’m not giving up.
IF ANYBODY HAS ANY INFLUENCE, PLEASE GET ANY AND ALL SCALE HOUSES OFF OF CHANNEL 36 TO 40. THE INTERFERANCE IS GREAT FOR ANYBODY USING THOSE CHANNELS.
It was a bad idea without any forethought of what they were doing. You will help the limited spectrum that we can play in. I don’t care how big the yard is, they NEVER consulted ANYBODY.
I never mentioned those guys, but if anyone has any influence, those BIG yards need to pay attention.
Mark
No BullShit Radio