[Touch Pro, Fuze ROM Development] mike-b:
I've been meaning to start a thread like this for a while, as I think it's more helpful to discuss radio rom performance for individual locations. I'm using an XDA Serra on O2 UK, so far not very impressed with radio performance.

I've got the stock O2 UK ROM, and I've tried radio roms 1.02.25.19 (stock), 1.02.25.28, 1.08.25.20M1, and now on 1.09.25.14 (Blackstone). My main criteria is GSM (voice) performance, which is paramount to me, and I live in a poor signal area, so where I am talking about radio performance I am specifically referring to 2g GSM1800 voice.

Compared to all my other (much older) phones - Vox, tornado, Nokia 6100, the Raphael has much lower signal strengh - permanently shows 1-2 bars less on the display, and always much lower in 'Field Test' & GSMTestMode tools. I believe that the signal strength indicator on the vox and Raphael (both WM6) operate on the same scale, but I could be wrong, that's why I also check the RSSI figures.

All of the four radio's above have been very similar in low signal performance, regularly dropping calls and hunting for signal where my other phones hold 2 bars all day long and rarely drop calls.

This leads me to the conclusion that weak radio performance is a hardware flaw of the Raphael, rather than rough software - I'm sure HTC have got the radio drivers 99.5% perfect pretty much from the off - they have afterall managed it with past devices.

I am also using a GSM repeater in my house - let me explain this a little further. Without the repeater I can get usable signal in one upstairs room in my house. The repeater has a panel antenna pointing out of this window towards the nearest base station. I then have the amplifier h/w and repeater aerial (rubber duck antenna) in roughly in the centre of the building. This works very well with all my other phones - I can make & receive voice calls anywhere inside the building with at least 2 bars of signal using my vox. The Raph struggles with calls almost everywhere in the building, other than right next to the repeater antenna (where I get 3 bars on the Raph, and 4 on the vox).

The GSM repeater gives me a good tool to assess signal strength ability of the handsets relative to each other. What I have found it that when placed right up against the repeater antenna, the Raph shows a slightly higher RSSI than the vox (although the vox appears to limit the gain more intelligently, perhaps to counter too high a signal?). As the devices are moved away from the repeater, RSSI falls off far more rapidly on the Raph than the other devices, which is part of what leads me to believe the radio hardware is the problem.

My findings so far:

Stock O2 Radio .25.19 did seem slightly worse than the others,

.25.14 seems slightly better than .28 and .20M1, but we are talking very small differences and could be just placebo effect.

.25.14 might appear to be better as it doesn't look like it's 'searching' as much, but when I come to make a call, the two bars of signal strength mysteriously vanish, viewing RSSI in fieldtest seems validate that .25.14 continues to show two bars when in fact the signal has dropped substantially.

With all radios, I seem to find that I get better signal strength with the phone horizontal rather than vertical - this is unusual as the handset antenna is usually tuned to work better vertically, because thats generally the position it's in when you put it to your ear.

I've never, ever seen a 3g signal with my Raph, and I travelled all over the country with it at Christmas. Maybe I was never in a 3g area the whole time. I don't think telcos are putting up many more 3g masts, so it looks like we will be relying on 2g coverage for the foreseeable future.

Turning off HSDPA on the Raph certainly saves battery, and it appears to help the 2g GSM signal performance as well. As I live in Cornwall, the chances of me ever getting any advantage from a 3g signal are very slim!

I've never managed to get any GPS signal at all from the built in GPS. Not with any of the above radios, or even fiddling with Advanced Config, GPS Test, GPSID settings, HTC GPS Tool. I can't even find the built in GPS device on any com port. Works fine with my external B/T GPS box. Either my GPS h/w is faulty or the O2 Rom disables it. Frustrating, as everyone else seems to get it to work to some degree at least.

1.10.25.25 will probably be the next radio I try, although from what others have said it's not a huge leap forward in GSM performance.

Has anyone compared GSM radio performance to the Diamond, Touch HD, or Rose devices? As much as I love the features of the Raph, I use my phone for my business, and the most important feature is phone performance for me, everything else is secondary. At this rate I am going to have to go back to the vox for phone, and use the raph for everything else. But that means I will have to carry 2 devices where one should cope.

Sorry for the hideosuly long post, but I've got quite a lot to say about raph radio performance.