vB Easy Archive - t616 antenna in T610....better RF???

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t616 antenna in T610....better RF???
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Posted by: blakebl

I've read some posts that claim the RF on the 616 is better than the 610. Has anybody ever tested this? I know they use different internal antennas -- has anybody ever tried putting a 616 antenna in a 610? I was thinking about buying a 616 off of ebay then selling my 610 if the RF is actually better, but www.globalmob.com sells the OEM 616 antenna for $13 so I may just buy that first and try installing it in my 610. The 616 may also be getting better RF because of the 850 support, if that's the case then it wont help me because I'm on T-mobile and I think they only have 1900 towers. Any advice or opinions is appreciated. Thanks.

Posted by: PhillyemtT3

First thing, don't try this at home LOL. The 616 and 610 run on different frequencies, therefore if you use a 610 antenna in a 616 you will end up blowing finals, same goes for a 616 antenna in a 610. The SWR's won't match up, and you're phone will stop transmitting one day down the road.
I wouldn't do this myself, however in theory the RF would actually be worse as the antenna wouldn't match the bandwidths for the correct wavelength antenna, causing the SWR's to jump around, in return causing more RF to re-enter the phone rather then being sent out into RF land. The reception may be better as it may be a "longer" antenna in theory, but your signal INTO the tower would be horrid.

-Jeremy

Posted by: costeen

i used to dabble in CB radios and SWRs were critical in output and radio life.i knew phones were rf but wondered about SWRs and how they worked out on these phone configurations.

Posted by: PhillyemtT3

Anything that transmits and has an antenna needs to take SWR's into account

including these phones, it's not as crucial with phones, as it would be on a CB, or (my favorite) an amateur radio pushing over 500w. However it still needs to be taken into account to get the most life from the phone. Even the saying "It worked fine on my friends phone for 3 years" means nothing, it could be fine on one, but kill another the moment it finds signal with a tower, so best to be safe

Posted by: merwin

I personally have done the T616 antenna in a T610 phone, and have had it in there and working fine for around a month. You get about a 5 to 10 dB improvement in signal (which is a decent amount). I've done the measurements myself of the signal.

The actual hardware of the antenna is incredibly easy to replace. It just pops out and pops in. The T610 antenna is labeled R1A, and the T616 is labeled R1B, which suggests that all it is is a newer version.

Doing this will NOT harm your phone (unless you break your phone taking it apart, of course).

Posted by: PhillyemtT3

Again, maybe not in the short term, but it will eventually. Trust me, I didn't go to college for Electronic and RF Tech for nothing.

The DB may be better for Rx, but your SWR's for Tx will be all screwed up, and will not retain the 1.5:1 ratio as the OEM antenna for the 616 is.

The antenna in the 616 is a Full wavelength on 850, which is the biggest concern for the frequency. It retains it's 1.5:1 SWR so long as the antenna is a full wave 850Mhz antenna inside. I'm not concerned with the other frequencies, as they're the same on both antenna's. The 610 is a full wavelength antenna on 900Mhz.

Now the problem lies by taking an 850Mhz Transmitter, and replacing it's antenna with one that is tuned for 900Mhz, what happens is the SWR's no longer maintain a 1.5:1 ratio, rather they jump to around 3:1, which is way too much RF going back into the Transmitter.

To dumb it down. You take a radio on 850, put a 900 Mhz antenna on it, instead of 500 watts of power leaving your radio, only 400 is, the other 100watts sits in your final transistors which overheat and WILL eventually fry, rendering the radio (or phone, same concept) as nothing more then an 850Mhz scanner, as the final transistors are blown, it will no longer be able to transmit.

So go ahead, put the 610 antenna on the 616, it may improve the reception, but the transmittion will be shot, and your finals will take a beating.

The choice is yours, people forget RF and antenna law when they do these sorts of things and will argue because they don't know. Now you do, do what you will.

Posted by: merwin

Wouldn't that only apply if you're using the 850/900mhz bands? I operate strictly in the 1900mhz area. I don't do any travel outside of the USA.

What you're talking about only applies if you're actually using the radio on the 850/900mhz frequency, right? When you're on the 1900mhz frequency, it's still using just as much juice, but with a better antenna.

Posted by: PhillyemtT3

True, wouldn't apply if you don't use the 850 band, nor the 900, but not everyone lives in a 1900/1800 area

However both antenna's would in fact and are in fact exactly the same on the 1900/1800 bands, therefore null n void of a new antenna, as it would really make no difference except maybe on reception, which I don't see why it would even work in the first place as the wavelength on both antenna's would be 100% identical.

However tomorrow for craps and giggles, I'm going to throw a 610 antenna in my 616 and toss it in the field strength meter, along with placing it in the SWR reader, maybe the oscilliscope, tomorrow at work. I'm quite interested, however in theory it wouldn't make any difference for both 1800/1900 bands, as they're the same wavelength antennae.

Posted by: paf

hey whats the FCC id on both the T616 and T610, then we can get SWR data from fcc.gov

-> by the way on the T61x the lower frequency is software controlled, not by hardware so they can be flashed either way,

that is the case for many modern dual band phones, they can be flashed to either NA or european frequencies, the hardware is designed to accommodate both sets of frequencies. probably meant for cheaper mass production

examples -> siemens c56/c55 motorola c350 (it doesnt even require flashing, only flexing)

Posted by: bigray327

Quote:

Originally posted by PhillyemtT3
However tomorrow for craps and giggles, I'm going to throw a 610 antenna in my 616 ...

Did it work?

Posted by: merwin

The power amplifier between the 850/1800/1900 and 900/1800/1900 is the same...

I opened up a few phones to checked.

Posted by: bigray327

I swapped out the antennas as described above and my T610 does, in fact, get slightly better reception. I held my 610 side-by-side with my wife's unmodded 610 and drove around town, and I consistently got one bar more than her. Sometimes her bars were yellow when mine were still green.

Was it worth the $20? Yeah, probably, since this mod is making the difference between "No Service" and sweet internet-surfing goodness while I'm at work.

Your mileage may vary.

Now I need to find someone in Houston to flash my firmware!

Posted by: verbal11

Quote:

Originally posted by PhillyemtT3
True, wouldn't apply if you don't use the 850 band, nor the 900, but not everyone lives in a 1900/1800 area

How can I find out if I live in a 1900/1800 area, or for that matter how do I know if I use the 850 band? I have T-Mobile in Los Angeles, and I'd like to try replacing the antenna if it will give me better reception. But your mention of damaging the phone if I use the T616 antenna and don't live in a 1900/1800 area concerns me.

Thanks

Posted by: TambourineMan

Merwin,

I have a T616 so I don't need a new antenna, but what I do want to check is the actual difference between the original R1A054 firmware and the R1B027 update.

I would like to be able to get a numerical db or percentage signal reading rather than depending on interpreting the bars as the firmware update may simply make the meter more optimistic rather than actually improving the reception/transmission by changing the lock on algorithm or somehow increasing power to the tuner/amplifier.

In another forum you said that to get the db readings in a T61x, there is a channel info menu that can be activated. How do I activate it?. Do I need to flash it with a hacked file, or can it be done by some combination of joystick movements and asterisk keys?

Posted by: skagen

Quote:

Originally posted by paf

-> by the way on the T61x the lower frequency is software controlled, not by hardware so they can be flashed either way,

I didn't realize that. I have a T616 - and if this is true, I'd love to switch it from 850 to 900mhz. Do you know how/where exactly I can get the codes or software or hardware to do it?

Posted by: vasu

any updates on this? I was thinking of doing this mod, but I don't want to blow out my transistors

-vasu