Antenna comment or suggestion

[WA4HHG]

I live on the outskirts of the Tidewater, VA area on the very west side of Chesapeake, VA. Have a BCD996XT, 536 and a 436. All are currently using the stock antenna, indoors. We have a very tall, 35' roof peak and I thought about mounting something to one of the vent pipes. Would like to hear Norfolk EMS/Fire and VA Beach EMS/Fire and maybe some Mil-Air.

Thinking about the MP Antenna Super-M Ultra Base:
https://www.theantennafarm.com/catalog/mp-antenna-08-ant-0861-6617

The MP Classic

or ??

Ideally, a rotatable LOG would offer the best signal recovery albeit on a single azimuth at a time. Plus, I don't want to go the rotor, etc.... route.

I COULD put the antenna on top of my tower @ 120' but.... that would mean a 365' cable run to get there. The resistive losses in 7/8 or even 1-5/8" hardline alone are prohibitive.

Amplified antennas are also a non-starter. We have a good bit of intermod in the area; I'm close enough to Norfolk to see into down town from the top of my tower.

So, I can listen to Chesapeake and Portsmouth Police / Fire / EMS is always interesting but would like to reach out a little further.

Thanks !

 

[mule1075]

DPD Productions - Base & Mobile Antennas for Radio Scanners: VHF, UHF, NOAA, Low-Band, 700 MHz, Police, Fire, Public Safety

Excellent Antenna

 

[prcguy]

I won't recommend what antenna to get at this point but I will tell you the MP Antenna Super-M Ultra Base appears to be deaf in the 800MHz range. I also don't see any improvement yet with the multipath claims they make for this antenna. Due to its construction I would not recommend it for long term use outdoors near the ocean. After a little more testing I will post more about its VHF/UHF capabilities.

 

[WA4HHG]

DPD Antenna

DPD Productions - Base & Mobile Antennas for Radio Scanners: VHF, UHF, NOAA, Low-Band, 700 MHz, Police, Fire, Public Safety

Excellent Antenna

Thank you, its on my short list. The specs don't quote 700-800 mHz coverage though.

 

[WA4HHG]

MP Antenna

700-800 MHz deafness is a deal killer. While I'm 27 mi inland from the ocean, am 1/2 mile from the Great Dismal Swamp and the humidity is something that has to be experienced to be appreciated.

Am not a fan of discone antennas, have always regarded them as something little more effective than a dummy load. Thought of building something like the Austin Ferret with its multiple resonant elements but I understand that antenna is more show than go.

I won't recommend what antenna to get at this point but I will tell you the MP Antenna Super-M Ultra Base appears to be deaf in the 800MHz range. I also don't see any improvement yet with the multipath claims they make for this antenna. Due to its construction I would not recommend it for long term use outdoors near the ocean. After a little more testing I will post more about its VHF/UHF capabilities.

 

[prcguy]

So now that I understand you need 700-800MHz plus airband and probably everything in between I will make a suggestion. A typical good quality scanner Discone is hard to beat for VHF air, VHF public service, VHF amateur, UHF mil air, UHF amateur through UHF public service. No other antenna for anywhere near the price will give you good performance across all those bands.

They typical scanner Discone leaves a lot to be desired above UHF, so my suggestion is to get a good Discone for VHF through UHF then a separate gain type antenna for 700-800MHz and combine them with a low loss diplexer. You will then have about the best you can get unless you spend some serious $$.

I have lots of big high gain commercial repeater type antennas for every band and combiners for every combination possible, and my go to antenna system for scanning is a commercial Discone for 100 through 500Mhz and a tiny commercial Discone for 500Mhz through infinity.

 

[abqscan]

Thank you, its on my short list. The specs don't quote 700-800 mHz coverage though.

Tuned: 118-137, 148-175 & 225-900 MHz

700-800 falls within the 225-900MHz.


I highly recommend this antenna!

 

[Ubbe]

Amplified antennas are also a non-starter. We have a good bit of intermod in the area; I'm close enough to Norfolk to see into down town from the top of my tower.

Could you please explain a little more about the intermod issue?
Is it something you experiance when you now have your scanners indoor and only use their own antennas?

It must be a really lousy chineese amplifier to get intermod in it. It's always the scanner that have the intermod issue and that's due to a too strong signal into it. I would suggest an antenna that focus on the weakest frequency you would like to receive, probably those EMS/Fire services you mention, then add a good $30-$50 amplifier and use RG6 coax and finish it off with a 1-3 splitter, you had several scanners, and always have a variable attenuator to each scanner, or if they are equal in perfomance you could use a single one before the splitter.

The variable attenuator are the secret to get a good reception. No scanner user that have an external antenna should be without one. Start with no attenuation and listen to a weak signal in analog mode and start adding attenuation to see if the signal to noise ratio starts to improve. Or if you have intermod on a frequency, start adding attenuation until the intermod is gone. You can always get rid of intermod by adding attenuation and as the scanner then had too much signal it probably had reduced reception sensitivity at other frequencies as well. If the intermod are really bad you have to attenuate so much that it will reduce other frequencies too much and you'll need to add some sort of frequency filter.

Broadcast and pager transmitters are the most common problem to intermod and poor reception and at least a 88MHz-108MHz bandstop filter are cheap and commonly available.

/Ubbe

 

[WA4HHG]

The Hampton Roads area has Norfolk Naval Station, Oceana Naval Air Station, Naval Security Group, Northwest, Langley AFB, Norfolk Southern RR HQ, Norfolk Naval Shipyard, Newport News Shipbuilding and drydock Joint Base Little Creek, and the list goes on. All of those, plus 6 or 7 city Fire, Police, EMS, FBI, USCG LANTAREA, and the state all have various radio systems. Port all those signals into the input of a wide-band ampifier and the amplification device is converted into an oscillator and the user ends up with a myriad of sum and difference signals mixed from any two or more of the aforementioned transmissions, none of them very readable. Feed that into the broad-banded front end of your typical scanner and you have an audio signal akin to gumbo.

Yes, it can be attenuated but that has little effect on the mathematical sum and difference frequency mixing of that many signals unless the receiver front end is very stable.

RF engineering has come a long way. In the environment I just described, most scanner front ends are robust enough to handle input from an antenna. In areas of low RF density, they will work ok with something under 15 db of preampliification. You can make the antenna and feed system even more robust by adding a common mode choke right at the scanner input which prevents feedline pickup. Here is a video demo I did to demonstrate the effectiveness of common mode chokes when used in conjunction with directional MW DX antennas: https://youtu.be/pZjA_aFv6Y0

Be sure to read the commentary below the video before watching the experiment on YouTube.

 

[dlwtrunked]

700-800 MHz deafness is a deal killer. While I'm 27 mi inland from the ocean, am 1/2 mile from the Great Dismal Swamp and the humidity is something that has to be experienced to be appreciated.

Am not a fan of discone antennas, have always regarded them as something little more effective than a dummy load. Thought of building something like the Austin Ferret with its multiple resonant elements but I understand that antenna is more show than go.

I had an Ausin Ferret--worked so poor I tore it apart and three it away. My discone worked a lot better.
(Though the Hustler discone was an almost unbelievable poor performer due to its design.) If you want broad continuous frequency omni-directional coverage, a discone is really your only choice. I you want broad directional coverage, a log-period is a reasonable choice. If you want omni-directional coverage but only certain bands or directional coverage of only certain bands, then there are antennas that can provide nice gain. One has to determine which of the above one wants, and then proceed accordingly or put up more than one antenna if there is a combination of those needs.