Hi Antenna guru's....

Can someone with the NEC or equal antenna simulator tell me what the impedance
of a dipole tuned for 28.4MHz is at 21, 21.25 and 21.450?

Also to other way around, what is the impedance of a 15m dipole cut for 21.25
as seen by a generator at 28.2, 28.5 and 29.0.

If I take this 10 meter dipole and attach a RG-58 cable to it, the
transformation of the reflected impedance to the sending end will vary with the
length of the cable and repeat every half-wave interval (take in account the
velocity factor of the RG-58 as 0.6).

What lenght of RG-58 should I use attached to this 10meter dipole to create the
highest SWR possible on 21.25 MHz?

My thoughts here is to have two dipoles attached to one feed, the first antenna
that the signal meets is the 15meter dipole. The second antenna will be
attached after another run of RG-58.

I hope to select the lenght of the 58 run between the two dipoles such that the
impedance reflected into the center of the 15 meter dipole is very high at
21.250.

I would hope to reach the same using the 10 meter band such that the 15 meter
dipole would present a high impedance to the 10 meter signal.

De KJ4UO