BCD436HP: Antenna upgrade for 436

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hotlava646

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Hello all, I have finally bought my first p25 scanner, the 436 after using uhf/vhf scanners. I got it up and going after a great lesson from a friend. My question is I know there are better antenna's out there. I did search the forums and see two particular ones. The RadioShack 800MHz Scanner Antenna and SMA SpectrumForce 700-800 MHz 2db Gain Portable. Well both are OOS and I can't even find them on ebay. Does anyone have any other recommendations? Thank you again.
 

marksmith

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The antenna that comes with the 436 is not a bad antenna. Some 800mz antennas will improve that band at the expense of others. The RS800 or Remtronix 800mz antenna do this. You need your adapter for the RS antenna, the other one comes in SMA version. I have also used the Spectrum Force in SMA.

Mark
536/436/WS1095/HP1/HP2/996T/996XT/996P2/396XT/325P2/PSR800/15X/others
 

W8RMH

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I have used these for over 20 years on portable scanners with excellent results - Comet CH-32 Miracle Baby. It is only 1.75 inches long and has an extended receive range of 118-160 MHz, 250-290 MHz, 360-390 MHz, 420-470 MHz, 820-960 MHz, 1260-1,300 MHz. and works great on 760-870 MHz as well.
 

SOFA_KING

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You will get a ton of personal opinions on this question. The answers will confuse you more than help.

Fortunately, I have a pile of antennas to test with. Much of what matters has to do with what bands you want to listen to. In my case VHF HIGH, UHF LOW and 800 bands were my target bands. And if you are truly doing a fair test, you need measure your antenna testing in a rock solid stationary position with NO MOVEMENT of the scanner, or your own body, to get fair results. Doing this in a couple of stationary positions will yield even better test results. And you need good weak signals on each band to get meaningful comparisons. Most of the antennas I tested did poorly at one or more of the bands I tested. For example, the much favored Diamond SRH77CA did poorly at 800, and is really tuned for 2m and 70cm ham bands, so that was disqualified. The Radio Shack 800 antenna is great at 800, but not at all acceptable on the other bands. And the Icom stock 2m/70cm antenna did pretty good on 800 and UHF, but not good enough on VHF. A standard telescopic antenna adjusted to 18" does fairly well, but is too bulky and rigid for portable use.

I tested several others that were not winners on all bands. The clear winner in my test was the Comet SMA-24. Unlike the Diamond SRH77CA, which did poorly on 800 MHz, the Comet did fairly well. Not as good as the single band RS 800 antenna, but a fair compromise considering all bands. And VHF/UHF bands did as good as the 18" telescopic antenna, which is about as good as you are going to get other than a single band (coil tuned) half wave, which is exactly what the RS 800 antenna is for 800 MHz(only). But the Comet did better on 800 over the telescopic...unless you shorten the telescopic to around 10 1/2", which is a 50 Ohm 3/4 wave. So something in the small base coil of the Comet works better for 800 than the Diamond. And the VHF/UHF wide-band performance is also not degraded by that matching coil. The SMA-24 is also nice and flexible, so it wins in that category, as well. Works for me!

That's my real world experience. I would like to hear if anyone else did the same type of test with the SMA-24. And if they did, I'd especially like to know if they found a better portable choice that worked at least as well on all bands, but exceeded in some way.

Phil
 

benburke

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I'm an AT&T retired digital technician. Any improvement with another antenna will be primarily for analog frequencies. With digital channels, your signal is either there or not. If the bulk of your listening frequencies are analog, you may want to experiment with a different antenna. Nevertheless, even though the expense is small, I don't think it would be worth it. I agree with marksmith. The antenna that came with the 436 is not shabby at all.
 

hotlava646

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Great info all. As I am learning I actually knew a few of the terms you all have said, lol. I should have mentioned a little more about what I am listening too. I know I am using TxWARN P25 system in the Houston area. All 800 mhz or 700 mhz police, fire, EMS frequencies. Among the older scanners I have I also bought a Baofeng which did its job quite nicely listening to vhf and uhf. I added a Nagoya antennae to it and the range was amazing so that's why I was curious about the 436. I am also now getting the 536. So I will pay attention to what towers come in the least and see if they are 800 or 700 and start from there. Many thanks..
 

SOFA_KING

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I agree that the stock antenna is not that bad. It's primarily a VHF antenna, but not too bad elsewhere. I also tested other scanner brand "stock" antennas and they all worked about the same, except the shorter GRE/Whistler type antenna from the PSR-800/WS1080. That didn't do so well. Then I tested a bunch of Motorola antennas for various bands and sub bands, and they worked great as single band antennas, but not multi-band. I wish I had the newer APX multi-band designed antennas to try. But the Comet SMA-24 works nicely on the three bands I tested. I don't have any local low band to test with, so I can't say what would happen there. Not being long enough, I would suspect it would (pardon the pun) fall short. Hmmmm...What would a 436 look like with a 73" whip on it? Kinda cool, I think. :D

Phil
 

dcisive

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I've got the 881 and 889's and they are excellent. However couldn't resist after seeing a video review of the
Diamond SRH320A 144/220/440 MHz Tri-Band Handheld SMA Antenna. I ordered one and it should be here later next week. Hoping it does well across the entire range. I KNOW it will below 800 but it's supposed to be covering that area as well so we shall see. I especially like the fact it was only 13" but has a nice center coil loading and is highly flexible so won't deform. We shall indeed see.
 

jonwienke

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I'm an AT&T retired digital technician. Any improvement with another antenna will be primarily for analog frequencies. With digital channels, your signal is either there or not. If the bulk of your listening frequencies are analog, you may want to experiment with a different antenna. Nevertheless, even though the expense is small, I don't think it would be worth it. I agree with marksmith. The antenna that came with the 436 is not shabby at all.
Seriously???

A better antenna will absolutely improve reception. Digital signals with lots of garbles or dropouts will clean up with a better received signal, and you will be able to pick up other digital signals that you couldn't receive at all previously. A better antenna won't improve reception of a digital signal that the inferior antenna received well enough to decode with a low bit error rate, but it will increase the range within which you can get error-free decode of a given digital signal.

Putting it in your terms, the digital signal will be "there" for greater distances and under more adverse reception conditions with a good antenna than it will be with a crappy antenna.
 

benburke

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Seriously???

A better antenna will absolutely improve reception. Digital signals with lots of garbles or dropouts will clean up with a better received signal, and you will be able to pick up other digital signals that you couldn't receive at all previously. A better antenna won't improve reception of a digital signal that the inferior antenna received well enough to decode with a low bit error rate, but it will increase the range within which you can get error-free decode of a given digital signal.

Putting it in your terms, the digital signal will be "there" for greater distances and under more adverse reception conditions with a good antenna than it will be with a crappy antenna.
Yes, seriously. The antennas for these scanners were designed for analog frequency transmissions. I haven't seen a design which will allow optimum results for both analog and digital channels. To my knowledge, there is not an antenna for the 436 which was designed solely for digital channels. The "rubber duck" antennas were designed long before digital transmissions for a wide frequency range (approximately 30 to 1000 MHz). Obviously, if the digital signal is of sufficient strength, and the radio's electronics are of good quality, it will do fine in receiving it, but the signal can't be improved. As previously stated, a digital signal is either there or it isn't. Yes, good error correction and error concealment technology may improve it some, but that has nothing to do with the antenna. I would not waste my time or money with trying a different antenna.
 

dcisive

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Woah Sofa_King. I was surprised to hear you say the stock 436 antenna was pretty good actually. I purposely didn't even put it on my new radio after reading so many people slam it as virtually worthless. I just went in and took it out of the box for the first time and put it on. Holy crud............it picks up everything as good as any combo I've yet tried. Perhaps I'm in a ideal area to the point where it does just fine. I rather like it's small profile. Diamond has a new one that is even smaller but has full coverage. I'll work with this for a while. Perhaps I wasted my $$ ordering that new Diamond I mentioned in another post here. It will be here later in the week so I'll have a chance to road test it. Man it had better do SOMETHING remarkable or I just wasted $45. Oh well...........so much for this hobby.
 

jonwienke

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Yes, seriously. The antennas for these scanners were designed for analog frequency transmissions. I haven't seen a design which will allow optimum results for both analog and digital channels.
If you're a radio engineer, you are remarkably ignorant of basic RF principles. The only things that matter to antenna design are the desired frequency range and the propagation pattern. The modulation type has no relevance whatsoever to the antenna design. 700MHz is 700MHz, regardless of whether the carrier is modulated with an analog FM signal or a digital signal.

There is no such thing as a "digital" antenna.
 

SOFA_KING

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Woah Sofa_King. I was surprised to hear you say the stock 436 antenna was pretty good actually. I purposely didn't even put it on my new radio after reading so many people slam it as virtually worthless. I just went in and took it out of the box for the first time and put it on. Holy crud............it picks up everything as good as any combo I've yet tried. Perhaps I'm in a ideal area to the point where it does just fine. I rather like it's small profile. Diamond has a new one that is even smaller but has full coverage. I'll work with this for a while. Perhaps I wasted my $$ ordering that new Diamond I mentioned in another post here. It will be here later in the week so I'll have a chance to road test it. Man it had better do SOMETHING remarkable or I just wasted $45. Oh well...........so much for this hobby.
They wanted $45 for that? I think they are marketing that towards the Kenwood tri-band radios, especially the new D-STAR radio. Why pick that one? I wouldn't expect it to do good on 800, but until you try it you will never know.

It's a balancing act with most antennas. When you add here, you usually take from there. But a universal rule (law of physics) is, "antennas shorter than a full quarter wave have negative gain". There is just no way around it. If you shorten it, you have to use coils to tune it to a narrower frequency point, so you loose any kind of "wide band" linearity, and often have dead spots (nulls) at various places. A quarter wave antenna at 155 MHz is around 19", and would need at least another 19" of ground plane to work properly. Matched end-fed half wave antennas (around 38" on VHF) eliminate the need for the ground plane, and that is why they make the best choice for portable radio use on a single band. Higher frequency bands have shorter wavelengths, so the resonant antennas get smaller. That is why the most popular performance antenna for 800 MHz is a end-fed half wave (the coveted RS 800 antenna), but it is NOT tuned to work below 800 MHz, so it's not a good choice for the 155 or 460 bands. Most multi-band antennas attempt to use harmonic relationships to add the higher bands to fundamental bands, but the more you play with coils and traps, the more you will see drastic peaks and nulls in tuning. That is why an antenna may be great in one place in the band, and terrible at another place. However, tuning is only one factor. Radiation pattern is another, and almost more important. Think of it this way...The radiation "lobe" of an antenna needs to be pointed at the intended station you want to receive. If it doesn't, you loose signal, and sometimes a LOT of signal. The science behind this is NOT guesswork. It's proven. Most respectable antenna manufacturers make polar pattern charts (showing exactly where the radiation lobe(s) favor), as well as tuning specifications. Providing these specifications used to be standard fare, but in this age of being "dumbed down" we seldom get that information any more...especially on "consumer grade" antennas. Instead, we get slick marketing to hoodwink the dumb@$$ consumer, and cleaver empty promises to bilk them out of their disposable income! (blood pressure rising...serenity now...insanity later). People need to demand full specifications again. Just using a cute name like "Watson" (from Sherlock Holmes) shouldn't be the "specification" that convinces you to choose that antenna over the many better choices available!

So, to recap, smaller antennas are shortened range antennas generally with lass bandwidth. A full quarter wave antenna, or better yet half wave dipole, has roughly unity gain and flatter bandwidth. Third harmonics (3X the tuned frequency) also match well and work ok. True gain means you are stacking multiple resonant elements (greatly multiplying the length) to compress the radiation pattern lobe towards the horizon (where most stations are located). Coils tune to one place in a band, but take from others. And finally...There is NO SUCH THING as a "digital antenna"! RF signal level is just that, and mode doesn't matter. That whole "digital antenna" thing was another marketing scam. If you want to understand what is really happening with antennas, go read (and look at) real specifications from professional antenna manufacturers. Anything else is pure guesswork and haphazard speculation.

Phil
 

sibbley

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Well said jonwienke. An antenna tuned closest to the frequency you are listening too will do better on analog or digital than a wide band antenna.

I use all tuned antennas for my scanners, with the exception of my ST-2. For business scanning, I use an antenna tuned to either 455MHz or 470MHz. Regardless of analog or digital, these antennas work best in the 450MHz - 475MHz range. For some local public safety I use an antenna tuned to 155MHz, this also works well on both analog or digital.

Your best bet is to use an antenna tuned in the band you monitor. In most cases. my tuned antennas were cheaper than most wide band antennas.
 

benburke

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If you're a radio engineer, you are remarkably ignorant of basic RF principles. The only things that matter to antenna design are the desired frequency range and the propagation pattern. The modulation type has no relevance whatsoever to the antenna design. 700MHz is 700MHz, regardless of whether the carrier is modulated with an analog FM signal or a digital signal.

There is no such thing as a "digital" antenna.
If your last sentence included the words, "for a scanner," then I would agree with you. However, since you're mistaken, I will simply end the discussion and wish you well. No, I'm not a radio engineer. I did work in radio forty years ago, but I only obtained an FCC third class radio-telephone license with a broadcast endorsement. As you may know to be a radio engineer one needs an FCC first class radio-telephone license. I retired from AT&T in 2011, as a digital technician and I did take pride in performing my job duties with utmost precision. I repaired and installed digital telephone equipment which included fiber optic multiplexers, DC power supplies, and digital pair gain systems. While I may be "remarkably ignorant" as you seem to know enough about me to use those words, on the other hand, I refuse to say anything negative about your knowledge and experience except that your people skills may need some fine tuning.
 

dave3825

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I have used these for over 20 years on portable scanners with excellent results - Comet CH-32 Miracle Baby. It is only 1.75 inches long and has an extended receive range of 118-160 MHz, 250-290 MHz, 360-390 MHz, 420-470 MHz, 820-960 MHz, 1260-1,300 MHz. and works great on 760-870 MHz as well.
I have been looking at that antenna but all I have seen it listed for is 144/440/900 MHz Tri-Band . Where is it listed with the extended ranges? Specifically, the 118-160 MHz range?
 

jonwienke

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While I may be "remarkably ignorant" as you seem to know enough about me to use those words, on the other hand, I refuse to say anything negative about your knowledge and experience except that your people skills may need some fine tuning.
I don't know anything about you except what you've posted. But none of that changes the fact that your assertion that digital modulation requires some special consideration for antenna design that distinguishes a "digital" antenna from an "analog" antenna in the same frequency range is completely wrong. All modulated RF is analog, a summation of sine waves within a specified range of frequencies. Given the same frequency and equal channel width, there's zero difference in the design requirements between receiving "digital" or "analog" signals until after demodulation--where the RF signals are converted either directly to an analog waveform, or into a series of numeric values that are further processed and decoded to an analog waveform.
 

benburke

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Jon, as most wireless communications done today is digital, the most important function of modulation is to squeeze as much data into the least amount of spectrum possible. This is known as spectral efficiency and it measures how quickly data can be transmitted in an assigned bandwidth. Logically, the greater the bandwidth, the more data can be transmitted. Antennas for scanners will receive both analog and digital signals, but I submit to you that a better antenna will be of greater benefit for analog transmissions. However, you are free to believe whatever you want.
 

Robertolson

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I've owned all the antenna's, & spent a lot of $$$$, the RS 200-0006 is on my 436 about 95% of the time, as it can do 800 band good and other bands buy just raising the mast.
 

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