Measured PSR500 sensitivity

[SCPD]

I just thought I would post some info that I got today for my PSR500.

It was connected up to a signal generator and the sensitivity was measured.

866 MHz 0.25 uV
512 MHz 0.5 uV
470 MHz 0.5 uV
406 MHz 0.45 uV
170 MHz 0.40 uV
155 MHz 0.25 uV
144 MHz 0.25 uV
136 MHz 0.25 uV
118 MHz 0.25 uV

All were in FM mode and 12 Db Sinad.

So .. to those that insist on putting high gain external antennas on their GRE scanner .... DONT DO IT, you don't need to as they are very sensitive already and you will just desense your radio.

 

[RKG]

I just thought I would post some info that I got today for my PSR500.

It was connected up to a signal generator and the sensitivity was measured.

866 MHz 0.25 uV
512 MHz 0.5 uV
470 MHz 0.5 uV
406 MHz 0.45 uV
170 MHz 0.40 uV
155 MHz 0.25 uV
144 MHz 0.25 uV
136 MHz 0.25 uV
118 MHz 0.25 uV

All were in FM mode and 12 Db Sinad.

So .. to those that insist on putting high gain external antennas on their GRE scanner .... DONT DO IT, you don't need to as they are very sensitive already and you will just desense your radio.

Any chance you have values for 20 dB SINAD?

 

[pro92b]

20dB SINAD is not a standard test but 20dB quieting is. The chart below compares several Uniden and GRE radios for 20dB quieting. GRE generally has relatively poor UHF sensitivity but is reasonably close to Uniden on the other bands. The PSR500 has exceptionally good 800 band sensitivity, improved over older GRE models.

[20 dB Quieting Test, All Channels NFM Mode except PRO-83 and PRO-2096 FM mode

Frequency PRO-2096 PRO-83 BC246T PSR500 PRO97* PRO2055 BCD396 BC796D BC780XLT BCD996
030.00000  0.31uV  0.32uV 0.28uV 0.28uV 0.33uV 0.27uV  0.33uV 0.34uV 0.44uV . 0.32uV
040.00000  0.26uV  0.29uV 0.30uV 0.24uV 0.24uV 0.24uV  0.30uV 0.25uV 0.45uV . 0.31uV
050.00000  0.26uV  0.29uV 0.29uV 0.24uV 0.26uV 0.25uV  0.31uV 0.25uV 0.43uV . 0.29uV
125.00000  0.30uV  ------ 0.38uV 0.35uV 0.29uV 0.29uV  0.30uV 0.34uV 0.50uV . 0.27uV
135.00000  0.31uV  ------ 0.36uV 0.31uV 0.28uV 0.28uV  0.34uV 0.31uV 0.43uV . 0.27uV
144.00000  0.28uV  0.33uV 0.32uV 0.35uV 0.28uV 0.29uV  0.27uV 0.35uV 0.43uV . 0.25uV
155.00000  0.28uV  0.31uV 0.33uV 0.34uV 0.28uV 0.28uV  0.30uV 0.29uV 0.42uV . 0.25uV
170.00000  0.31uV  0.33uV 0.33uV 0.37uV 0.32uV 0.33uV  0.30uV 0.34uV 0.46uV . 0.25uV
250.00000  0.87uV  ------ ------ 0.61uV 0.48uV 0.49uV  0.32uV 0.27uV 0.40uV . 0.28uV
300.00000  5.50uV  ------ ------ 0.78uV 0.54uV 0.57uV  0.35uV 0.32uV 0.55uV . 0.26uV
350.00000  2.20uV  ------ ------ 0.85uV 0.51uV 0.70uV  0.33uV 0.34uV 0.24uV . 0.33uV
410.00000  0.40uV  0.27uV 0.29uV 0.50uV 0.37uV 0.53uV  0.35uV 0.23uV 0.25uV . 0.32uV
460.00000  0.42uV  0.29uV 0.32uV 0.53uV 0.40uV 0.39uV  0.39uV 0.23uV 0.26uV . 0.32uV
500.00000  0.60uV  0.27uV 0.30uV 0.71uV 0.55uV 0.60uV  0.39uV 0.24uV 0.32uV . 0.31uV
765.00000  2.10uV  ------ ------ 0.37uV ------ ------  0.47uV ------ ------ . 0.39uV
855.00000  0.48uV  0.36uV 0.38uV 0.29uV 0.59uV 0.44uV  0.44uV 0.41uV 1.20uV . 0.29uV
935.00000  0.49uV  0.38uV 0.40uV 0.43uV 0.44uV 0.44uV  0.57uV 0.43uV 1.40uV . 0.32uV

 

[GTR8000]

It was connected up to a signal generator and the sensitivity was measured.

Ah this is the same guy going around recently claiming that Uniden models are 18 dB "less sensitive" than GRE models.

The GRE PSR500 was 18 DB more sensitive than the Uniden 396 models. Thus when you turn on the ATT .. they are about the same. However on an external antenna the GRE would overload.

Total hogwash. 18 dB less sensitivity would make the Uniden models practically deaf for anything other than strong or local transmissions. That is most certainly not the case. I've compared the two neck and neck on identical frequencies, and the Uniden always pulls in the same weak stuff the GRE does, and often it pulls in even weaker signals than the GRE.

The fact is that GRE has a terrible front end that is extremely prone to overloading from nearby strong signals. This has been proven time and time again. If Uniden was pumping out scanners that were 18 dB less sensitive than the competition, they wouldn't be around for very long. :roll:

 

[pro92b]

Ah this is the same guy going around recently claiming that Uniden models are 18 dB "less sensitive" than GRE models.

Total hogwash. 18 dB less sensitivity would make the Uniden models practically deaf for anything other than strong or local transmissions. That is most certainly not the case. I've compared the two neck and neck on identical frequencies, and the Uniden always pulls in the same weak stuff the GRE does, and often it pulls in even weaker signals than the GRE.

The fact is that GRE has a terrible front end that is extremely prone to overloading from nearby strong signals. This has been proven time and time again. If Uniden was pumping out scanners that were 18 dB less sensitive than the competition, they wouldn't be around for very long. :roll:

I think my measured data shows that the two manufacturers are roughly similar for raw sensitivity. Focusing on particular bands does show some differences with Uniden generally being slightly better.

Regarding front end overload, GRE has a big weakness on the VHF-HI band because they use one less front end filter than Uniden. This allows FM broadcast to desense VHF-HI reception in some locations. Regarding the RF amp and mixer stages, neither manufacturer delivers stellar performance for resistance to overload.

 

[GTR8000]

I think my measured data shows that the two manufacturers are roughly similar for raw sensitivity. Focusing on particular bands does show some differences with Uniden generally being slightly better.

Regarding front end overload, GRE has a big weakness on the VHF-HI band because they use one less front end filter than Uniden. This allows FM broadcast to desense VHF-HI reception in some locations. Regarding the RF amp and mixer stages, neither manufacturer delivers stellar performance for resistance to overload.

Your chart reflects what can be expected in the real world.

Anyone claiming GRE has "18 dB better performance" than Uniden either A) has no clue what they're talking about or B) has cherry picked the data by focusing on one specific frequency the GRE outperforms the Uniden on.

Even if B were true, I find it astonishingly hard to believe that any modern unit by either manufacturer would have an 18 dB loss on any portion of the spectrum they are capable of receiving. The built-in attenuator on these units de-senses them by about 20 dB, and anyone who has played with the ATT button in a real world setting knows just how much loss that really is.

 

[SCPD]

Your chart reflects what can be expected in the real world.

Anyone claiming GRE has "18 dB better performance" than Uniden either A) has no clue what they're talking about or B) has cherry picked the data by focusing on one specific frequency the GRE outperforms the Uniden on.

Well I am going to test the 2 Uniden scanners again (the 396T and 396XT) .. as well as the PSR800 scanner. But it will be about a week or two before I will have access to the test equipment again. So I will post the results from those 3 scanners to give you real world results. Then you can take things as they are .....