Antenna testing terrible srh77ca

Status
Not open for further replies.

darticus

Member
Joined
Feb 19, 2008
Messages
740
Location
Sparta, New Jersey
Been testing a Diamond SRH77CA for over 2 months now. My testing showed me that this is a terrible antenna. Many have recommended it to be one of the best. Test it yourself! I can't believe how badly it tested as even compared to the stock HP antenna and many other cheap Radio Shack antennas. When compared to other hand held scanner antennas it seems to only receive 1/4 of the transmission that are received with a RS 800 antenna a RS 9 section tele antenna a BC246T stock antenna and a RS roof top discone. So bad that I returned it and got another to test. Same thing TERRIBLE! Actually silent in the 800 band (State Police). I am looking for someone to tell me I'm wrong after you test it. I was told this is the antenna to buy. Its rated very good and it stinks! Out 20 bucks but would have liked to get the antenna advertised and recommended. Don't even know what to do with it. Some even said maybe it was being overloaded with the power of transmissions that were close BS. Do yourself a favor compare it. Ron
 

n5ims

Member
Joined
Jul 25, 2004
Messages
3,723
One issue with your testing is asking an antenna designed as a dual band (2 meter/70 cm) ham antenna to work great on a frequency band it wasn't designed for (800 MHz band). This is kind of like saying that a Ferrari 599 GTO is a horrible car since it doesn't comfortably hold my family of 6 nor can it pull my gooseneck horse trailer.
 

gewecke

Completely Banned for the Greater Good
Banned
Joined
Jan 29, 2006
Messages
7,473
Location
Illinois
Been testing a Diamond SRH77CA for over 2 months now. My testing showed me that this is a terrible antenna. Many have recommended it to be one of the best. Test it yourself! I can't believe how badly it tested as even compared to the stock HP antenna and many other cheap Radio Shack antennas. When compared to other hand held scanner antennas it seems to only receive 1/4 of the transmission that are received with a RS 800 antenna a RS 9 section tele antenna a BC246T stock antenna and a RS roof top discone. So bad that I returned it and got another to test. Same thing TERRIBLE! Actually silent in the 800 band (State Police). I am looking for someone to tell me I'm wrong after you test it. I was told this is the antenna to buy. Its rated very good and it stinks! Out 20 bucks but would have liked to get the antenna advertised and recommended. Don't even know what to do with it. Some even said maybe it was being overloaded with the power of transmissions that were close BS. Do yourself a favor compare it. Ron
Umm....you're wrong? It's a great antenna on the bands it was designed for! 2m/440mhz primarily.
If you're testing it for receiving at 800mhz. freqs then forget about it!
Did you ever check the band specs to see IF 800 mhz. was listed? :wink:

73,
n9zas
 

darticus

Member
Joined
Feb 19, 2008
Messages
740
Location
Sparta, New Jersey
Thanks, Maybe you have corrected me and I am wrong. I just know its terrible for a hand held scanner and it was recommended very highly for its use. The packaging for it has me confused as it does say it will do the job for 800 band. If I wrong again sorry if I'm right this has a false advertisement but its good for something else. Ron

One issue with your testing is asking an antenna designed as a dual band (2 meter/70 cm) ham antenna to work great on a frequency band it wasn't designed for (800 MHz band). This is kind of like saying that a Ferrari 599 GTO is a horrible car since it doesn't comfortably hold my family of 6 nor can it pull my gooseneck horse trailer.
 

Attachments

eorange

Secret Agent Man
Joined
Aug 20, 2003
Messages
2,309
Location
Cleveland, OH
Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_3_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8G4 Safari/6533.18.5)

Hmm, this is puzzling. I've had the SRH77CA for over 6 years and it's a great performer on all bands. Right now I'm listening to Ohio Lake, Geauga, and MARCS 800 MHz systems with my PSR-500 and this antenna, and it does great. In fact it's also my main civ and mil air antenna, as well as VHF lo/hi and 2m/440.

It really is a good performer. Have you tried it on another radio?
 

WA1ATA

Member
Joined
Jun 18, 2010
Messages
416
Location
Fairhaven MA / San Jose CA / Kihei HI
What is in the base of the antenna besides the connector?

A 1/4 wavelength at 146MHz is around 19" and it seems that the SRH77 is more like 15" in length. I assume that it has a very small coil .... perhaps just a single spiral loop.

Has anybody opened one up?
 
Last edited:

KI4VBR

Member
Premium Subscriber
Joined
Aug 4, 2009
Messages
217
Location
Palm Harbor, FL
My $.02

I have been using that antenna on a 396XT with limited succues.....I think the only reason I keep it on there is it flexes a lot better than stock and doesnt beat up on the SMA connector on the radio like the stock antenna does. I actually think it doesnt do so well compared to the stock antenna, just my experience though.

I does matter a lot as to where you are doing your testing and comparing apples to apples.....meaning the exact frequencies in a scan group. I can say that the new antenna on the HP-1 works better than the stock antennas on my handhelds. Again, this is the case in my testing environment, which.... unless you are my neighbor, your testing lab is going to look a lot different.

If you are going to throw the antenna away, why not put it to good use and start trimming it to see if you can move the resonant point closer to where you would want it. Not implying that you are going to can the antenna, but if you were thinking that.....it might be a good learning exercise.

Best luck to you and it is great that you are sharing your experiences with the srh77ca. That is one of the reasons we all flock to RR, to read real reviews by real people.

Vince
 

ridgescan

Member
Joined
Apr 1, 2008
Messages
4,609
Location
San Francisco, Ca.
Ron have you tried that radio with that antenna in another location? It could be that the antenna is so "good" that it is now drawing more local RFI and sqooshing signals on 800? Just guessing.
 

n5ims

Member
Joined
Jul 25, 2004
Messages
3,723
Thanks, Maybe you have corrected me and I am wrong. I just know its terrible for a hand held scanner and it was recommended very highly for its use. The packaging for it has me confused as it does say it will do the job for 800 band. If I wrong again sorry if I'm right this has a false advertisement but its good for something else. Ron
That picture helps me to understand your confusion. Looks like the marketing department make the packaging so it overstated the antenna's design specs (as they often do to try and sell more units). It's not that the antenna won't pick up 800 MHz signals, it's just that it doesn't do it very well. My MFJ version of the same antenna doesn't indicate it will also work at 800 MHz, only the two bands it was designed for.

Here's another thread on this topic that confirms that the SRH77CA works well on VHF-Hi and UHF, but not so hot on 800 http://forums.radioreference.com/antennas-coax-forum/24605-stock-uniden-vs-diamond-srh77ca.html. I wish you'd have seen it before getting yours to better set your expectations (and possibly allowing you to get a different antenna at the time).

Although you may not have much success, you may try calling the warranty number since there's a 1 year warranty on the Diamond. Clearly the package indicated good 800 MHz results which the antenna simply doesn't provide. Perhaps a few returns for this issue may at least fix the packaging.
 

gewecke

Completely Banned for the Greater Good
Banned
Joined
Jan 29, 2006
Messages
7,473
Location
Illinois
Granted that the SRH 77 is advertised to receive other than the vhf/uhf ham bands, but how well it does this really depends on many variables, such as distance from the operator, type of system being received,etc.
Have you tried adding a groundplane to the antenna? One way would be to mount the SRH 77 on a magnet mount with a female bnc and attach it to a flat steel surface.
I have done this with my MFJ-1717 for a indoor antenna in case of storms. The MFJ-1717 is similar to the diamond and It works quite well for aircraft, LMR on uhf, but marginal at best above 700mhz.


73,
n9zas
 

DPD1

Member
Joined
Jul 24, 2005
Messages
1,994
They're always going to put a bunch of other bands on there for RX... Because technically any antenna will do that. But it's the TX that's going to be best.

That one is usually the best for most stuff, but it probably would not be best for iffy 800 stuff. But no antenna is going to get everything perfect. You have to choose what's most important.
 

KE5MC

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
929
Location
Lewisville, TX
Vince,
Without knowledge of how it is constructed. I suspect it is more than just a base-loaded antenna with nothing more than wire from the base to tip. From base to midpoint it has a thicker section that steps down from that mid-point to the tip. It could just be mechanical reinforcement, but I am thinking more along the lines of a coaxial sleeve construction.

It would be interesting to disassembly a "known" bad antenna simply to understand the why of it's current external appearance.

Mike


<snip>...

If you are going to throw the antenna away, why not put it to good use and start trimming it to see if you can move the resonant point closer to where you would want it. Not implying that you are going to can the antenna, but if you were thinking that.....it might be a good learning exercise.

<snip>...

Vince
 

KI4VBR

Member
Premium Subscriber
Joined
Aug 4, 2009
Messages
217
Location
Palm Harbor, FL
It would be interesting to disassembly a "known" bad antenna simply to understand the why of it's current external appearance.

Mike
True Mike....isnt that what our hobby is all about, experimenting? I love that kind of stuff and will waste all kinds of hours trying to make things work just a lil better. I do wish the companies would listem more to these folks here at Radio Reference and ham operators when it comes to product input.
 

nanZor

Active Member
Joined
May 28, 2009
Messages
2,807
Don't feel bad - my Diamond SRH320A has similar packaging, and it also is definitely not optimal for 800 mhz. The RS 800 mhz duck beats it by far. Even the oem duck that comes with the Uniden 396 does a better job, which seems resonant around 155 mhz.

DPD1 is right on about real performance coming from the bands designed for transmit. In my case, the tri-band SRH320 was a bit more useful for the low end of mil-air monitoring just above 225 mhz than the R77 due to the 320A being designed for the amateur 220 band as well as 2m / 440. But above 300 mhz, it's a wash between the two.

Still in the end all ducks are a compromise. :)
 

darticus

Member
Joined
Feb 19, 2008
Messages
740
Location
Sparta, New Jersey
Thanks all for the new comments. I thought that maybe Diamond went a little to far saying it was good for 800 as it is if the station is outside my shack. Now if I'm stuck with this thing what on a scanner will it be good for? Please in English all you brainiacs? Is it good for CB, HAM, What? I'm serious I don't know. Maybe the company will send me an exchange for something I could use for the scanner thats better than my stock stuff. Ron
 

WA1ATA

Member
Joined
Jun 18, 2010
Messages
416
Location
Fairhaven MA / San Jose CA / Kihei HI
Please in English all you brainiacs? Is it good for CB, HAM, What? I'm serious I don't know.
It was optimized for the 2 meter ham band of 144-148 and the 70cm band of 420-450MHz, but will also do a reasonable job of receiving nearby frequencies.

The VHF band from 150MHz to 163MHz is close enough to the 2 meter band to work well.
It should also be good in the 460-490MHz range, since that range is just above the 70cm ham band.

The 118-136 civil airband is reasonably close to the 2 meter band. I should be very good towards the high end of the band, and OK even to the lower end of 118MHz.

As you've discovered, it isn't optimized for 700/800/900 MHz signals.

So, in plain English, I've told you what you've already figured out. :)
 

eorange

Secret Agent Man
Joined
Aug 20, 2003
Messages
2,309
Location
Cleveland, OH
I disagree. On 800 MHz, I get just 1 or 2 bars less than the RS 800 MHz antenna. Absolutely no problem for trunked receive on 800, and 900 is just as good (paging, occasional phones, etc).

On every other band, it does very well as a wideband receive antenna. Super strong on VHF Lo/Hi, 440, and the entire civ and mil air bands (138-144 MHz and 225-380 MHz). Again, this after using it for 6 years on all types of scanners and wideband receivers.

In this thread, I think only myself and the OP actually own this antenna; everyone else is just reading the specs and drawing assumptions.

To the OP: how far away is the 800 MHz tower that you're trying to receive? Are you in a valley, or is the line-of-sight to this 800 MHz tower pretty flat?
 

WA1ATA

Member
Joined
Jun 18, 2010
Messages
416
Location
Fairhaven MA / San Jose CA / Kihei HI
On 800 MHz, I get just 1 or 2 bars less than the RS 800 MHz antenna.
With most scanners, 1 or 2 bars is a pretty significant difference in signal strength. Of course, if you have more than enough signal to start with, then 6 or 12dB down doesn't matter.

If you are willing, I'm curious about the relative performance of the RH77 vs. a 3" or 3.5" long wire stuck into your antenna connector. Copper is better, but if you don't have that available, the wire ties for bread and other plastic bags is about the right diameter to insert directly into a BNC connector (or an SMA to BNC adaptor if your radio is SMA).

You may think I'm joking, but in reality, I've found that a simple 1/4 wavelength chunk of wire, even without ground plane, is a reasonable antenna.

Another surprisingly simple yet good performing antenna is to cut the coax braid off of the last 19" of a coax cable. The 19" of center conductor that are unshielded is a 1/4 wave element at 2 meters; a 3/4 wave element at 450MHz, and seems to work well at 800MHz although it probably has a strange radiation pattern.
 

darticus

Member
Joined
Feb 19, 2008
Messages
740
Location
Sparta, New Jersey
I'm sure Diamond rated this antenna being next door to the 800 station. I'm in the mountains so things get tough. I can receive the 800 on the stock HP antenna on the HP and also with the stock BC246T antenna on the BC246T but no reception with the diamond on the same receivers. If I lived close to everything I probably would get all they advertised that the diamond should get but I live a distance from some stations. A piece of wire might get these channels outside the station building also! Disappointed in their advertisement and how they did their testing to get the advertisement. Maybe Diamond will take it back on trade for a usable antenna. Ron

I disagree. On 800 MHz, I get just 1 or 2 bars less than the RS 800 MHz antenna. Absolutely no problem for trunked receive on 800, and 900 is just as good (paging, occasional phones, etc).

On every other band, it does very well as a wideband receive antenna. Super strong on VHF Lo/Hi, 440, and the entire civ and mil air bands (138-144 MHz and 225-380 MHz). Again, this after using it for 6 years on all types of scanners and wideband receivers.

In this thread, I think only myself and the OP actually own this antenna; everyone else is just reading the specs and drawing assumptions.

To the OP: how far away is the 800 MHz tower that you're trying to receive? Are you in a valley, or is the line-of-sight to this 800 MHz tower pretty flat?
 
Status
Not open for further replies.
Top