SDS100/SDS200: SDS100 HORRIBLE reception at Alliance Ft. Worth air show

[Mike445]

Try wide inverted on air band!

Ill
Give it a try!
Mike

 

[lzielasko]

So here's the short of it. I was at the Fort Worth Alliance practice show today and brought an old PRO-107 and my Uniden SDS-100. the 107 KILLED the SDS-100 performance wise. I had all filters OFF on the 100. No attenuator on. Squelch set on 2. Both radios had a Diamond RH-789 antenna at the same length. Both radios had the same channels programmed. The SDS-100 works flawlessly on everything else I've used it for until now. No problems at all. This is the first airshow I brought it to. It didn't pick up distant transmissions the 107 would snag crystal clear. The transmissions that it did pick up weren't as clear as the PRO-107. There was plenty of noise. I tried (briefly) to use the normal and invert filters and neither seemed to change things. Does ANYONE have any suggestions I can try tomorrow? I will be using my PRO-107 as my primary airshow radio but would like to get my SDS-100 where its performing like a top of the line radio should. Thanks y'all
Mike

I love my SDS100; however, I prefer my ICOM IC-A25N (pictured on right) when it comes to VHF airband monitoring.

 

[palmerjrusa]

The "wide invert" filter setting on my SDS100 makes the difference between no signal and a clear signal with 100% readability.

 

[Mike445]

Okay. So the SDS100 performance was slightly better today. Are use the stock rubber duck antenna and wide invert filter. We were sitting right next to the air boss and blue Angels COM cart. The RSSI readings were around -30 to -50. I didn’t attenuate the signal though. It was usable with the duck antenna. As we were leaving I still had my PRO-107 running and as we approached the portable tower pictured that scanner locked up on every channel. Completely unusable. I wonder if this was causing part of the problem!?

 

[jonwienke]

Pretty sure that thing emits a crapload of RF. Curious what is in those domes...

 

[nanZor]

That's not good. The difficult part are to make an antenna that's very wide banded and stilled tuned without loosing performance.

Actually it is good for it's intended purpose, which is to NOT be wideband, and concentrate solely on the civil airband for which it was intended. Out of band reactance is very high, which attenuates neighboring bands not of interest *at the time*.

Common use in the past was to help kill FM overload on dual-conversion 10.7mhz IF scanners, which got nailed by FM, and also by neighboring amateur packet stations, along with commercial vhf pagers. With more modern gear, a lower noisefloor when used with the scanner makes it also worth considering.

The whole point was that it makes a TERRIBLE multiband scanner antenna, unless you are interested in the civil airband only.

In the ops case, he might find this useful when visiting airshows and only listening to civil air, or possibly very nearby mil-air that just plows it's way through.

In other words, the right tool for the right job at the time. Instead of speculation, find a friend who has one, and try it. Be adventurous, buy one instead. I promise you'll like it. It's not just simple empirical stuff or guesswork.

 

[Ubbe]

Actually it is good for it's intended purpose, which is to NOT be wideband, and concentrate solely on the civil airband for which it was intended.

I wasn't detailed enought. I meant wide banded enough to cover the whole VHF airband. A standard antenna do not do that without a signal loss and have a too hight SWR at the band edges to be comfortable used with a transmitter.

What antenna manufactures then can do are to make the antenna less efficient, sometimes by introducing a resistor in the antenna circuit, to make it more wide banded but with a loss in performance compared to a similar sized standard antenna that are more narrow banded.

/Ubbe

 

[Mike445]

Pretty sure that thing emits a crapload of RF. Curious what is in those domes...

Oh yeah. Insane amount of RF. It was wall to wall noise on every channel when I got close to it with the PRO-107. I’m gonna guess that was part of the issue with the SDS. I’d love to know what was in those domes!
Mike

 

[KE5MC]

AT&T logo on side of van and many cables going into each dome suggest to me a mobile cell tower. I've never really seen one, just a s.w.a.g.

 

[hiegtx]

AT&T logo on side of van and many cables going into each dome suggest to me a mobile cell tower. I've never really seen one, just a s.w.a.g.

The AT&T logo on the van supports your cell tower identification. Possibly a mobile cell site, to provide additional coverage capacity at the air show.

 

[Ubbe]

It has a micro wave link that connects it to another cell site. It's often that events out in the open don't have enough cell capacity and they then put a temporary transportable cell site there just for that event.

/Ubbe

 

[mikewazowski]

The "spheres" on top are beam forming antennas used for LTE or 5G. The panel antenna could be LTE or 3G or possibly 2G. There's a small link dish on the side of the tower as well.

 

[cmdrwill]

C O W Cell site On Wheels. With lots of pepole using there cell phone cameras at the event the normal Cell service is over loaded.

 

[Xray]

I love my SDS100; however, I prefer my ICOM IC-A25N (pictured on right) when it comes to VHF airband monitoring.

Would not be very useful at airshows without milair freqs, nice looking radio though