My sensitivity test for a radio may not be scientific, but it’s real world. I try to receive a repeater that’s 60 miles away. I’m standing in my driveway with my 7550, & 7550e. I hear the repeater on both radios. One step to the left, & the repeater on both radios is gone. One step back to the right, & I’m hearing the repeater on both radios again. No difference between the 2 radios no matter what the brochure says. The 6550 will not receive the same repeater from the same spot. But either way, since the repeater is 60 miles away, while the 7550 hears the repeater, & the 6550 doesn’t, none of the radios get into the repeater, so what good is the extra sensitivity? The big plus with the Gen 2 radios is the full UHF 403-520 coverage vs 403-470, & 450-520 on the Gen I HT’s. And while not a 7550e, those of us on 900 MHz despise the 7580e as Motorola deliberately locked out the 902/927 ham band, but the 7580 works great there, so the 7580’s are more desirable, & sell for more.
Stating it doesn't make a difference in your case doesn't change the fact that it might make a difference for someone else's case. As in, my case.
I totally understand where you're coming in terms of Motorola making deliberate nonsensical choices.... like the bolt antenna. Aside from that, for VHF/UHF the fact remains, a 4 dBm improvement translates to improved digital voice quality in fringe areas, vs no voice at all in some situations.
At 60 miles you should know its all about the repeater, not your portable. Measuring radio performance by "how well it can hear a repeater" its always doomed to succeed. A portable alone will never reach 60 miles while the user is walking at ground level, unless, of course, the person is walking atop of a tall mountain.... but most people don't perform their daily lives on a flat desert, or atop a mountain, most of us live in suburban/urban terrain with hills, and in places where if there is no infrastructure, you're limited by what your radio (and the other radios) can do, so every dBm you can muster counts.
Question: Have you measured the RSSI on both radios when these radio unmute? Please, do so. I am curious to see what kind of RSSI you are getting from both radios.
Well, ISOTEE tests are easy to do, and produce fairly accurate results; those tests are performed by repeater installations to evaluate how well they are working, and you can do the same for your radios. It explains a lot of the results you're seeing quite well, too.
As for the 6550 not receiving, that is normal, but that is b/c the XPR7550e has a measurable 10 dBm average advantage under most conditions, in VHF, based on dozens of RSSI readings obtained during every test we performed. You can verify this yourself, too, by putting all your XPR radios in RSSI mode (push left left left, then right right right) . (or up up up, down down down, on the SL7550) You enter RSSI mode, which tells you the signal strength as measured by the radio at whatever channel you have selected, radio works normally, you just get an RSSI screen. The 6550 also has a very tight squelch alignment too, so it won't be as good as the 7550 for weaker signal work.
To conclude: The 7550 non E is not a bad radio, never said that. I simply stated that after evaluating both, and given the fact that these cost about the same as the E model, used, I went with the E model.
IMO whoever is going for a used XPR7550 radio just should go for the E model, you never know when you might need those extra 4dBm.
G.
