Two antennas on same mast: Discone and FA pro stick


#1

Ok because of limited sky view options I am considering using one construction grade PVC tube (highly UV resistant) for two antennas. The problem is the down sloped redials of the discone cover the Pro Stick. Now “cover” is a loose term because the Pro Stick is still able to see 95% plus of the sky at any one time. Since both antennas are receive only I think this will not reduce the FA antenna’s performance. I also hope that the Pro Stick will “see” through the PVC and not create a dead spot as a metal pole would.
On the other end of the house will be my 2 meter VHF and 70 CM UHF broadcast antennas.

Any thoughts?
Bob


#2

Yes, it may negatively impact the FA antenna.

If either antenna was for TX as well, it would ‘smoke’ the other receiver’s front end.


#3

images
The distance between antennas should be approximately greater than the wavelength.


#4

Wow nice setup (yours?) but what is the use for what looks like two identical antennas. Maybe each antenna is cut to a different frequency?

Per your guidelines We would have two meter separation in the aircraft receive frequencies (broadcast not possible/legal obviously) and a full 1090 Mhz wavelength is so short as to not be an issue as to placement of second antenna except for being shadowed.

I don’t think I’m ready for a guyed tower yet. Maybe after I address HF with a vertical then come back to look a tower. Last year in my previous house had limited space but this property is nearly 800 feet long so might setup some long antennas instead of vertical HF antennas

Definitely looking forward to getting these antennas up on the roof and off my back deck.

Thanks for the reply,
Bob


#5

This photo I found on website of a manufacturer antenna masts. It’s just a demonstration of opportunities.
This is common practice. Another picture from the Internet:

In your case there will be a shadow from the mast.
The mast will close the horizon, approximately, in the sector about 45-60 degrees.
If you move the antenna away from the mast, then due to diffraction, the shadow will become smaller or disappear.


#6

Another example


#7