I recently purchased a 2003 S430, and am very happy with it overall.

I do have a few things to do...

One of the minor problems was that my cell phone had poorer performance inside the car. A little investigation revealed the special heat-control window glass that also hinders radio performance, including cell phone and GPS.

Since my home has marginal cell reception anyway, I wanted better cell performance. I decided to try a cell phone booster, in this case a Wilson Sleek 4G-V (for Verizon). I installed the system today, and did a minor amount of testing.

The booster claims to improve performance in three ways: An antenna outside the car (and those windows!); an amplifier for reception; and a booster for broadcasting. (I am not an expert in this field, and may well make a mess of this, but will be happy to hear any corrections.)

The benefits of an outside antenna are obvious, especially for those of us who have the special glass in our cars. I do not like the antenna provided with the booster! I like the performance improvement, but I do not like the cable running out the rear door and across the roof. I hope to do something about that soon, namely using the rear-bumper antenna built into the S430.

The reception amp increases the signal strength, then wirelessly links it to the phone. The phone must be resting in the booster, basically in contact with it. Reception is the only part of the system that I have actually tested so far.

First thing that I learned - bars mean virtually nothing. I found how to measure signal strength on my new phone (Razr Maxx HD), and used that to decide whether the booster actually did anything.

Sitting in my drive, phone in the car as usual (no booster used), I saw fluctuating readings for 4G (or LTE) reception, such as -112dBm, -106dBm, -103dBm, etc.

The dBm scale is logarithmic, which means that 3 dBm doubles or halves the field strength. Lower numbers are better.

I slipped the phone into the booster, and the numbers instantly changed. I still saw fluctuating readings for 4G/LTE reception, but now the numbers were -93dBm, -91dBm, -89dBm, -87dBm, etc. This gave an improvement of -10 to -15dBm. A -10 dBm improvement is roughly 10 times stronger, a -15dBm improvement is roughly 30 times stronger. The reception bars on the phone display sometimes showed one more bar, sometimes not. The Command phone display never changed, even with 30 times the field strength.

I repeated the brief tests on the 3G network. Reception is reportedly better on the slower network, and the numbers supported that. With no booster in use, I saw readings of -88dBm and -89dBm pretty consistently. When I slipped the phone into the booster, the readings immediately went to -66dBm, -68dBm, -65dBm, -64dBm, etc. This gave an improvement of about 21dBm, or a level 128 times stronger on the 3G network. Again, the improvement was not shown by changes in the reception bars in the phone or car displays - one bar most of the time, occasionally two bars on the phone, none on the Command display.

If I were depending upon the bar display, I would have immediately packed the Wilson up and sent it back! The phones testing display showed a very different picture, and I am confident that the booster does what it claims for reception.

I haven't tested broadcasting, and am not sure that I can. The claimed improvement will be easier for the booster to achieve, though. From what I could find, a hand-held usually puts out less than 100mW. The Wilson puts out 1.8 Watts...

I pulled everything out of the phone compartment in the center armrest except for the puck and its holder. The puck, booster and cell phone fit nicely, and I can pop the small lid open to operate the phone if necessary. (I use the Voice Command system for the phone.)

Next project is to get the booster hooked to the car's antenna, so I can get rid of the tacky cable on the roof.

Comments welcome!

 

Well, bogalot and Warren were correct in their concerns.

I bought a connector to fit the Sleek and installed it onto the antenna cable in the center console, and hooked the bumper antenna to the Sleek. Didn't work at all. I removed the trunk-mounted TeleAid/phone switch and hooked the antenna directly to the MB compensator. Success! Sorta...

Using the Wilson antenna on the Sleek, I saw a 25 dBm improvement in the 1x voice range, and 28 dBm in the 4G data range. This is a great improvement - over 500 times the original signal strength!

Using the stock MB bumper antenna on the Sleek, I saw a 24 dBm improvement on the 1x voice range, which is great - but the improvement in the 4G data range is only 9 dBm. This is better than nothing, but nothing like the improvement with the Wilson magnet-mount antenna.

A long conversation with a very helpful Wilson engineer didn't give me much hope. His opinion is that there is no way to improve the stock antenna - it simply isn't designed for the frequency range that I need. He suggested that I install a Wilson trunk-lip mount and antenna. Not too pretty, but better than the cable across the roof. No idea yet of the cost of parts.

Investigation will continue...

 

Anyone had any experince with non Verizon cell phone boosters?

 

I would expect the non-Verizon boosters from Wilson to perform very much like their Verizon models. they have a good rep in the business.

I did some antenna testing with the Sleek and the standard S430 equipment...

Bare Razr Maxx HD inside the S430: 1x -92.0 dBm; 4G -119.8

Using the Sleek 4G-V:

w/ Sleek roof antenna - 1x - 65.7 dBm; 4G -93.2 dBm
w/ S430 rear bumper antenna & compensator - 1x 68.3 dBm; 4G 110.8 dBm
w/ S430 rear bumper antenna, compensator removed - 1x 76.6; 4G 100.1
w/ Sleek antenna under bumper 1x -71.2 dBm; 4G -96.6 -dBm

For those not familiar with the strength measurements, these are are from the cellphone. The measurements are field strength, and are logarithmic, so a 3 dBm change either doubles or halves the field strength. Higher values are better - e.g., -90 dBm is twice the field strength of -93 dBm, and -84 dBm is eight times as strong.

So I get about 32 times the field strength on the 1x voice frequencies if I use the Sleek 4G-V with the S430 antenna with the TeleAid switch and the linear compensator removed; and about 125 times the field strength on the 4G data frequencies.

This requires that you either get an adapter to hook the S430 antenna lead to the Sleek, or change the connector on the antenna lead. You also need a mini-UHF female/female adapter (also called a barrel connector) to connect the antenna lead in the trunk around the switch and compensator.

On the other hand, I can use the Sleek magnetic-base antenna, with the antenna lead run out between the rear door and the body, and across the roof.
This give a field strength 500 times as strong as the bare phone on the 1x voice frequencies, and the same improvement on the 4G data frequencies! A tuned antenna is a beautiful thing as far as performance is concerned, not so much on visual appeal.

If I use the car's antenna cable from the Sleek to the trunk, and then adapt to the Sleek antenna, I can put the antenna under the car, or I can run the cable out between the trunk lid and the body and put the antenna on the trunk.

I tried temporarily putting the Sleek antenna under the car, forward of the rear bumper. This gave a field strength strength 128 times the bare phone, four times better than the S430 antenna on the 1x voice frequencies, and on the 4G data frequencies, I saw about 256 times the bare phone strength and about double the field strength of the Sleek and the car antenna.

If I put the magnetic-base antenna on the trunk, I get the same 500 times better signal on both frequencies. Looks like I may have to get used to the appearance of the little stub antenna on the trunk...

 

Why don't you have a professional mount an antenna on the roof and avoid the exposed cable? You get the ground plane effect from the roof and not the directional effect of a trunk or bumper mount. Try picking up the ARRL mobile antenna guide for proper placement. I am a ham and have been mounting antennas on my cars since the '60s. Do it proper and get on with it. What are you using for a field strength meter to get those readings? OR an inline meter? RF engineer since a kid....

 

Thanks for the suggestions and comments. I do wish that I knew a little more about the subject - but not enough to do serious study.

On pro antenna installation:
1) $$$ It would be a complicated installation.
2) I don't like the appearance.
3) While I very rarely take the car thru a car wash, I would have to remove the antenna every time.
4) It appears I can get satisfactory performance with the tiny Wilson antenna at an additional cost of $7.95 for a cable adapter. No idea how much performance I will lose due to the directional effect, though.

The Motorola Razr Maxx HD has the capability of telling what network it is using - 1x, 3G or 4G (LTE). The 1x voice is always there (if there is any signal at all), and 3G vs. 4G depends upon signal strength of the LTE network, which is the default. The phone also gives the signal strength of the networks in -dBm. Since phone performance is the only goal, I am assuming that the phone measurement is good enough for my purposes.

 

Nowadays everything has a solution to overcome and tackle the problems.

For your better signal coverage boosters act as a savior. But, now boosters are available in different qualities and coverage also for you vehicles and smart homes.

Isn't it really a great news to know.

If you are facing reception issues just go for it....