TriSquare TSX300 Review

[Moriarty]

I have the following preconception: the lower the frequency, the better the range. I understood that higher frequencies are absorbed/attenuated faster, especially in outdoor environment, so in theory a 900MHz radio should have a lower range than a 450MHz one with the same power (at least in outdoor conditions, which is what I'm interested in). Is this incorrect?

[jwilkers]

Originally Posted by Moriarty

I have the following preconception: the lower the frequency, the better the range. I understood that higher frequencies are absorbed/attenuated faster, especially in outdoor environment, so in theory a 900MHz radio should have a lower range than a 450MHz one with the same power (at least in outdoor conditions, which is what I'm interested in). Is this incorrect?

You aren't too far from the truth. The higher you go in frequency, the more the "line of sight" rule comes into play. As such, you need a better antenna system or higher one to overcome obscructions.

UHF does have a tendancy to "bounce" off metal, and find its way around buildings and such. As such, it is great for use inside buildings, and in dense urban areas.

VHF is better suited to outdoor, suburban environments, as it can penetrate some obstructions better; but doesn't have the ability to bounce, like UHF does.

Public safety has in the past used VHF for rural areas, and UHF for larger cities. This has been effective.

Each band has its good and bad.

[Hawke]

Greeting All,

Sounds like a very nice review of the TSX300s. I have a pair on the way now. I was curious as to if anyone has yet tested these units head to head against the Motorola DTR410s, the only other FHSS handhelds I'm aware of.

I found some info/reviews here:

http://ticom.livejournal.com/104713.html

(Pertaining to the DTR410s: In this review the user purports to have gotten a 2 mile max range out of the DTR410s, along with some other interesting information regarding range.)

and here:

http://www.trisquare.us/images/media...talTwo-Way.pdf

Some very interesting information. Spectrum analyzer displays of both the TSX300 and DTR410 RF output and banwidth along with some other interesting tidbits. The TSX300 seems to spread its bandwidth out over an approximate ~6.5MHz bandwidth whereas with the DTR410 it is approximately ~8.5MHz. A synchronization carrier can also clearly be seen with the TSX300, just adjacent to the upper-most hop frequency (more susceptible to CC jamming?)

It would be nice to know the precise hop time of both radios, although neither manufacturer seems to provide this information. But from what I've discovered thus far, it would seem to be in the neighborhood of 2-3Hz (@ a 300-400 mS hop time).

The Motorola DTR410 clearly has a better "ruggedness" to it, but as for me, I am more interested in communication performance/range than durability of the unit.

And last but not least, is the rather significant difference in price. The lowest price I have found for just one DTR410 is ~$239, whereas two TSX300s can be purchased for around ~$80-$90. It begs the question, would the performance justify the price?

Hawke

(02/18/08 - Please see my corrections and review below)

[jwilkers]

Word is Trisquare is planning on a "ruggedized model". Both radios use different, proprietary schemes. They both get the job done and probably perform in a comparable fashion.

It would be interesting to see what frequency the synch signal is on.

[lfudenna]

I have now used these for two conferences that my company produces. We were using anywhere from 8 to 12 at a time in both a 7 story building and a 2 story building.

I would have to say that I am not overly impressed as far as reliability goes. It seems like between 2 and 4 of them do not work very consistently with the rest. I have had a couple users complain that they don't hear transmissions sent to them, while they can hear someone else's radio nearby. I have tried multiple channels but it does not seem to make a difference. I am happy with the range of them and glad to read that they are supposed to automatically reset themselves if they lose frequency (I was resetting the channel hoping that would help).

Battery life has been pretty good and I will continue to use them (since I have invested in 12 of them). The ones that did work, performed well in the 7 story building. I haven't used the text message feature much because we are just too busy at our conferences to play with that feature.

I am happy to give more details to anyone interested in buying these in the future.

[Mark]

I would like to correct the misconception from the Nov. 2008 PopComm article about FHSS. It stated that the TriSquare eXRS radio used a 'sync' signal (showing a analyzer plot). The TriSquare eXRS radios do not use a seperate sync signal. The "sync" signal shown in the plot is not a sync signal, but is actually just one of the hopping frequencies within the particular 50 frequency hopset. Hope this clears up any misconception.

On another note to lfudenna, TriSquare would be very willing to replace the 2 to 4 units that do not seem to be operating correctly. lfudenna should contact TriSquare's service department at service@trisquare.us for replacements.

Mark at TriSquare

[jwilkers]

Thanks for clearing that up. I kind of was scratching my head when there was evidence of a separate signal... that would mean dual transmitters, not to mention the fact this could defeat the whole interference rejection benefit of FHSS.

[Frank]

Mark,

I just want to say thank you for being a member of the forum and listening to your customers concerns. The level of service that TriSquare is providing is exceptional and one that I wish many companies would follow. Just to let everyone here know you have always been available for any questions that pop up that my limited knowledge has no clue about.

lfudenna,
Take Mark up on his offer on the returns. I know that when they are getting returns back they are trying to figure out the issue instead of just saying its a bad unit and chunking it. This way they will improve on future generations. If you get a chance post a review of the TriSquares on the forum. People love to hear "real world" reviews.

[Hawke]

I now have both the TSX300 and Motorola DTR410 FHSS radios. I'll do a complete vs. review with ranges, etc, including spectrum analyzer plots if I ever get the time. As for now there is NO sync signal with the TSX300s. The dwell time is approximately 300 milliseconds or so giving it a hop rate of about 2.5-3 hps. Both radios hop a total of 50 channels. The DTRs hop at around 5 or 6 hps and actually utilize the entire ISM band from 902 to 928MHz whereas the 300s are more squeezed in around 907 to 923, give or take.

[Hawke]

Here are some spectrum analyzer plots for both the TriSquare TSX300 radio and the Motorola DTR410. The RBWs were first set at 1Mhz, 280KHz, and then 15KHz respectively. The spectrum analyzer in each case was set for Peak Hold and each capture is an average of transmission over a period of 15 seconds.

TriSquare TSX300


TSX300 - 1MHz RBW - Peak Hold - 15 sec.




TSX300 - 280KHz RBW - Peak Hold - 15 sec.





TSX300 - 15KHz RBW - Peak Hold - 15 sec.




Motorola DTR410


DTR410 - 1MHz RBW - Peak Hold - 15 sec.


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