Hamstick/HamTenna (MFJ 1610T) is very wide band, and has been used for both 10m and 11m without retuning.
Not wanting to get
@Littlecloud319 too hopeful here, I have attached the MFJ "manual" for this antenna. There is a note that states:
NOTE: Bandwidth and VSWR will vary due to mounting location. Roof mounts, trunk groove mounts, and trunk lip mounts are recommended. The poorest mount is a bumper mount. If your installation has a VSWR over 1.5:1 at resonance or you need to operate over a greater bandwidth, a tuner may be required.
While that note lacks specifics in the way of measured SWR to a frequency and then plotting the SWR curve (or use an Antenna Analyzer to make life easy), it begs for additional information.
Referencing my first response in Post #4 above, I stated:
Hi @Littlecloud319, you are looking for a single antenna that will cover both 10 Meters and 11 Meters with an SWR of less than 2:1 over both bands. That is a bandwidth of 29.7 MHz (top end of the 10 Meter band) minus 26.965 MHz (bottom end of the 11 Meter band) which is a 2.735 MHz spread. A single antenna is going to be hard to find that can do that spread and has an SWR of 2:1 or less across that spread. The antenna would need to be specifically designed for 10 Meter and 11 Meter operation. I don't believe that antenna exists.
While the MFJ-1610T might be able to have
some of the 10 Meter and 11 Meter bands covered with a reasonable SWR, I seriously doubt that it can cover the 2.735 MHz spread at a SWR of 2:1 or less
without retuning or using a tuner (as the note in the MFJ-1610T manual states). A quarter-wave stub at the two frequencies cited above would be:
29.7 MHz (top end of the 10 Meter band) ----------> 7.88 feet
26.965 MHz (bottom end of the 11 Meter band) ---> 8.68 feet
That is a difference of 0.8 feet or 9.6 inches. Just with the sheer length difference of 9-5/8th inches, one could almost visualize that a quarter-wave stub cut to the middle of the spread or (7.88+8.68)/2 = 8.28 feet or 8 feet 3-3/8 inches needing to be adjusted
± 4-13/16th inches to the theoretical match points on either side is probably not going to exhibit a 2:1 SWR or less across that frequency spread; i.e. bandwidth.
Possibly, just maybe, a 2:1 SWR or less could be achieved over the entire CB bandwidth and picking up the low end of 10 Meters for CW operation but that is still stretching things a bit.
Bottom line? I just don't see any single antenna covering both the 10 Meter and 11 Meter bands with a 2:1 SWR or less across the entire spread if re-tuning the antenna length and/or the use of an external antenna tuner is not permitted.
Fortunately, the OP has decided to stick with just one band for the antenna in question.
73, Dave K4EET