Testing longer whips on a Little Tarheel II
Вставка
- Опубліковано 25 бер 2015
- A comparison of the stock whips and longer ones with the Little Tarheel 2. Its only a basic test, not scientific at all and conditions weren't the best but gives an idea. Each time the whip was changed the antenna was retuned. End result is you can't beat more wire in the air. As gain on RX is usually reciprocal on TX, increasing from stock to 6ft and using 100W gives a transmitted signal similar to running a 400W linear on the stock antenna configuration. At £13/$20 its the cheapest performance upgrade you'll get.
The gains on 40m and 80m were even more pronounced but I was unable to find a beacon to use for comparison. Conversely the higher the frequencies, the less the difference. I would expect around 3-4dB on 10m for example.
A 6-7ft whip is really worth using if you are willing to sacrifice 6m. - Наука та технологія
Good demo Conor....am about to order a Tarheel and go mobile with my TS480SAT so will get hold of the longer whip too..73 Paul G4AFU.
Just what I was wondering about. Thanks
They say that the gains are more pronounced on 80 meters and with the 10-12 foot whip 160 is possible. I just got mine last week after a 3 month wait. I'm thinking of setting up a rig with grounding so that I can try it on the base transceiver. No point in leaving it out all the time for the thieves to get. It might work well as an alternate base antenna when not in the vehicle.
Have the same setup with a medium length whip. Wondering why you didn’t set the radio to AM for WWV.
have you had any problems getting on 80mtrs with yours TH? i got the tarheel extra long stinger and still doesnt tune 80 so not sure whats up.
I had a TARHEEL II & it tuned 80 meters with ease with a 54” whip as it did all of the other bands through 6 meters.
I would think that grounding is the issue.
@@9999plato i dont think it is grounding. i have the antenna on a L bracket screwed into my tool box on the truck and the tool box is grounded to frame in 2 places with braided wire the body of the 480 is under pass seat and grounded to frame. thats what has me stumped i think i`m doing everything right. next thing im going to do is clean the coil itself. i saw a video of a guy using alcohol to clean off the coil/rings and recheck all my connections again.
"100w in gives a TX signal similar to 400w into the stock whip". That's sort of a wonky way to express it. More accurate - The stock whip results in something like 5watts ERP for that 100w transmitter. A 6 dB improvement would be 20w ERP. There is no "Gain" in a screwdriver or any shortened antenna. Simple antenna concept is, the more any antenna is shortened (compromised) the more LOSS it will present. If you put a 23 ft whip on that screwdriver (a quarter at 10MHz) you'd have a 3dB loss over a half wave dipole. That half wave dipole is only 2.15dB gain over the theoretical iso antenna. 3dB loss, subtracted from 2.15 db gain is -.85dB "gain" (negative gain) over an isotropic antenna. Ain't no "Gain" going on with any mobile antenna under about 50 MHz, simply because we can't get anywhere near resonant length. RF apeture is tiny on a mobile HF antenna. ANY screwdriver, or any other mobile antenna, of a given length will perform exactly like any other antenna of the same length. It might be more weather or vibration resistant or have different cosmetics or mounting schemes. But in terms of RF pixies flowing, 24 inches equals 24 inches equals 24 inches. Thanks - Lumpy
He was very clear that the gain was relative to the stock antenna, not when compared to a dipole properly tuned and at the correct height. Read the text under the video. Anybody who has passed their test knows that short antennas are compromised when compared to dipoles or any other antenna that is much larger. In the case of mobile HF antennas, screwdriver antennas, particularly well made ones make the best of the limited choice of compromises. I'd have and would always choose a Tarheel or Scorpion antenna over ham sticks or any other sort of loaded antenna that have a very narrow bandwith.