Let's talk antenna masts

[WSHH887]

Thinking more about a base station.  I'm in a pretty good spot with the only blind area being the top of a peninsula to the west. The blind area is from approx. 200° to 280°.  And I sit on top of a hill.  Not much I'm going to be able to do about the blind spot transmitting on simplex.  But honestly the rest of the way around the compass has pretty good line of sight down the coast and inland to the foothills north of downtown L.A.  

I happen to have an unused flag pole from a project I never finished.  I haven't measured it but I figure it's about 15' and made from aluminum.  Properly set in cement, would this make a good mast?

[WRUE951]

12 minutes ago, WSHH887 said:

Thinking more about a base station.  I'm in a pretty good spot with the only blind area being the top of a peninsula to the west. The blind area is from approx. 200° to 280°.  And I sit on top of a hill.  Not much I'm going to be able to do about the blind spot transmitting on simplex.  But honestly the rest of the way around the compass has pretty good line of sight down the coast and inland to the foothills north of downtown L.A.  

I happen to have an unused flag pole from a project I never finished.  I haven't measured it but I figure it's about 15' and made from aluminum.  Properly set in cement, would this make a good mast?

i have a Harbor Freight Telescoping flag pole mounted on my 5th wheel trailer (rear ladder mounted) that i slide a home brew Copper J-Pole with 3D printed clamps. This set up is for a portable repeater when camping.   Fully extended im getting about 20-25' and with no obstructions around me i get pretty decent coverage.  It doesn't take much to hamper the signal, a few trees will kill the signal quality.  You should see the same type results.  

[Socalgmrs]

Sure. Sounds good.   I put all my antennas in old satalite dish mounts left behind.  

[WSIA887]

My wife gets me 25'-30' telescoping flag poles for $50 and less from Temu. They work great!!

[marcspaz]

In my opinion, it really depends on your expectations. 15 feet gets you about 5.5 miles to the RF horizon. 35 feet will get you out to about 8.5 miles. 50 feet gets you about 10 miles.

[AdmiralCochrane]

9 hours ago, marcspaz said:

In my opinion, it really depends on your expectations. 15 feet gets you about 5.5 miles to the RF horizon. 35 feet will get you out to about 8.5 miles. 50 feet gets you about 10 miles.

As I understand it, that is to the physical visible horizon, but RF propagation usually follows the curvature of the Earth some fraction beyond the visible horizon.

[SteveShannon]

4 minutes ago, AdmiralCochrane said:

As I understand it, that is to the physical visible horizon, but RF propagation usually follows the curvature of the Earth some fraction beyond the visible horizon.

That’s correct.  For UHF it’s several percent further than the visual horizon.

[BoxCar]

48 minutes ago, AdmiralCochrane said:

As I understand it, that is to the physical visible horizon, but RF propagation usually follows the curvature of the Earth some fraction beyond the visible horizon.

 

37 minutes ago, SteveShannon said:

That’s correct.  For UHF it’s several percent further than the visual horizon.

About 15% at most. Figure close to 10% but it's all dependent on terrain and weather.

[WRYZ926]

I would at least try to get the antenna up higher than the house if possible. Not everyone can get antennas higher than trees in the area. There are all kinds of options when it comes to antenna masts.

A study flag pole will definitely work as will chainlink fence top rail or 1 5/8" fence posts with couplers. Satellite dish/J mounts also work well. Some j mounts are 1 5/8" diameter and can be extended using couplers and 1 5/8" fence posts. 

Just remember to properly secure any mast with wall clamps and guy wires/ropes, depending on installation, to keep them from falling.

I made a mast from 1 5/8" fence posts for my Comet GP-9. I used j mounts for my Comet CA-712EFC and HF cobweb antenna. I used an eight foot piece of 1 5/8" fence post on the j mount to get the cobweb up  a little and it is secured with guy ropes.

[MarkInTampa]

I'm running a 30ft flag pole from Home Depot for a mast with a GP-6NC. For a bit more stability it's also anchored to the house. I ordered a telescoping flag pole but they sent me a sleeved sectional (6 5ft 2-1/4" sections) by mistake. Didn't send it back, figured it would be more solid than the telescoping version and by loosening the clamps on the house I can remove or add sections by myself so it wasn't a big deal. I thought I could get away with no guy wires but it seemed to sway a bit more than I would like at 30ft so added some. Dropped it to 10ft or so with the antenna attached and it made it through a direct hit from hurricane Milton.  

 

[LeoG]

15 hours ago, marcspaz said:

In my opinion, it really depends on your expectations. 15 feet gets you about 5.5 miles to the RF horizon. 35 feet will get you out to about 8.5 miles. 50 feet gets you about 10 miles.

https://www.everythingrf.com/rf-calculators/line-of-sight-calculator

[tcp2525]

A Rohn 25G makes an excellent light duty mast, just pick your height and get the amount of 10' sections and a top section to get off to a great start. 

[WRUE951]

3 hours ago, MarkInTampa said:

I'm running a 30ft flag pole from Home Depot for a mast with a GP-6NC. For a bit more stability it's also anchored to the house. I ordered a telescoping flag pole but they sent me a sleeved sectional (6 5ft 2-1/4" sections) by mistake. Didn't send it back, figured it would be more solid than the telescoping version and by loosening the clamps on the house I can remove or add sections by myself so it wasn't a big deal. I thought I could get away with no guy wires but it seemed to sway a bit more than I would like at 30ft so added some. Dropped it to 10ft or so with the antenna attached and it made it through a direct hit from hurricane Milton.  

 

Nice free standing but that wouldn't last a minute here in the High Desert today..  We are seeing 50 mile an hour gust today..