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TN-Tom · 12-21-2009, 03:21 PM

I have installed an FT857D with an ATAS Screwdriver 120 in our Winnebago Adventurer 38J. The antenna is mounted on the ladder using PVC pipe and grounded to the coach frame using 10 gauge stranded wire. The radio is grounded to the steering wheel mount under the dash. I can't get the antenna to tune, either, auto-tune or manual. This is true on all bands. I can receive very well, however. When the radio is tuned to 29.600 Mhz the SWR is 5.3. When I'm tuned to 7.200Mhz, the SWR is 17.2. Using my analyzer the antenna will tune to 169.23 Mhz and an SWR at 1.0. Then analyzer continues to give me the same numbers regardless of the frequency I use and press "auto-tune" once the radio is hooked to the antenna again.
Does the whip move up and down or is there a coil that moves internally in the larger black portion of the antenna? I'm at a loss. Any thoughts?

12-21-2009, 03:21 PM	#1
TN-Tom Retired/Senior Member Join Date: Jun 2009 Location: Pleasant Hill, TN Posts: 9	ATAS 120 won't tune ...... I have installed an FT857D with an ATAS Screwdriver 120 in our Winnebago Adventurer 38J. The antenna is mounted on the ladder using PVC pipe and grounded to the coach frame using 10 gauge stranded wire. The radio is grounded to the steering wheel mount under the dash. I can't get the antenna to tune, either, auto-tune or manual. This is true on all bands. I can receive very well, however. When the radio is tuned to 29.600 Mhz the SWR is 5.3. When I'm tuned to 7.200Mhz, the SWR is 17.2. Using my analyzer the antenna will tune to 169.23 Mhz and an SWR at 1.0. Then analyzer continues to give me the same numbers regardless of the frequency I use and press "auto-tune" once the radio is hooked to the antenna again. Does the whip move up and down or is there a coil that moves internally in the larger black portion of the antenna? I'm at a loss. Any thoughts?