Mounting antenna upside down?

[Danny37]

If I mount an antenna upside down will it affect performance? I have a very tight space I can run an antenna through and it seems like if I mount it upside down it would be more easier. It's a scanner antenna, no transmitting whatsoever. Any thoughts?

 

[nd5y]

Not enough information. What kind of antenna and what is it going to be mounted on?

 

[Danny37]

Not enough information. What kind of antenna and what is it going to be mounted on?

It's a one of those tram window mounted antennas, I want it to droop over the window on the outside from the top so I can still have use of the window. Also I'm thinking about spray painting it white so it more stealth. I live in a coop apartment and I can't mount an antenna outside and this is my best resort.

 

[prcguy]

Most antennas will work about the same upside down but most will also have problems outdoors with water getting into areas and causing problems. If the antenna is indoors no problem. You also have to be aware of the coax exiting the antenna and make sure it goes up and away from the antenna to avoid affecting the pattern.

I've seen some fiberglass antennas that actually filled up with water because they were used upside down.
prcguy

 

[Danny37]

I'm also reading that these through glass antennas have a lot of loss due to the fact there's no direct and grounded connection. I don't know what other options I have at this point, it would be nice to listen to repeaters 20 miles away, like in my old place I had an outdoor antenna and I could listen to Newark police from Brooklyn clear as day. Now it seems like that won't be possible.

Another thought that came to mind but that would mean that I would need to keep my window ac unit in all year round, mounting a magnet mount antenna on the ac unit. Good idea?

 

[KE5MC]

Depending on your listening needs if all on one bearing and narrow bandwidth an indoor beam might be an option. Easy to make and try out to see if that works.

Mike

 

[jonwienke]

Mounting upside down means your coax is more likely to interfere with the signal. Also, if your window has an energy-saving coating, a glass mount antenna will not work.

 

[popnokick]

Try this antenna. It will cost about $15 and 20 min of your time to try it so no great loss if it doesn't work for you. It's used by a lot of RR members and there is extensive info on it here in the RR forums. Here's the RR Anntenna Wiki page with the details. Scroll down the page to the wire version -
Homebrewed Off-Center Fed Dipole - The RadioReference Wiki

 

[Chronic]

I have seen scanner antennas that mount to windows and such with suction cups , might be a option

 

[jonwienke]

None of those will work if the window has a modern energy efficiency coating. It's a metal film that will block RF signals.

 

[popnokick]

The OCFD works through walls if no aluminum-backed insulation was used in the wall. Also in attics that don't have significant metal obstructions or metal roof. Highest window in the structure is first choice; if it doesn't work there it is easily moved to a place where it does work, since the wire version of the antenna is extremely portable. People roll them up, put them in suitcases, and hang them in hotel rooms.

 

[Danny37]

You guys are awesome, there's so much I can work with now. I know it's stupid of me to do so now but because I'm so lazy I ended up putting a magnet mount I had laying around from RadioShack and putting it on a cookie sheet up high in the corner of the room facing the open skyline. It's been receiving really well and I'm pulling in jersey stuff. I didn't account that I'm now 20 meters above sea level compared to my old place that 5 meters above sea level with a lot of obstruction. I can only imagine what I would be able to pull if I had a proper outdoor antenna. I'm still having trouble pulling things further north just like my old place, not sure why. If I can recieve from north jersey from here I should be able to pull in westchester. Still have to figure that out.

 

[KE5MC]

Outside antenna usually takes care of two issues. Building obstructions and height above ground. Which issues is better taken care of depends on the building and height. 20m is a good start and might not be much better outside unless the structure has internal metal support elements or metal siding.

Nothing wrong with an antenna on a pie sheet. I have a dual band outside for most of my xmit work, but inside I have a pizza pie sheet and antenna to supplement SDR and scanner activites.

Mike

 

[lmrtek]

Naturally, a on glass antenna would only work on single pane glass which is rare to find these days.
But upside down isn't an issue.
You can buy a ribbon coax jumper that will let you get coax outside and the window will close