Anyone know about antennas?

[BigBodyQ45]

Due to the fact that that infiniti had the little mishap with the intergrated car kit. I am forced into getting one hard wired. I want run an antenna but dont want to look like a cop with a big thing on the outside. How well do the inside glass ones work? I have tint, is that a very big deal or no? Any info is awesome.

Thanks,Dave

[Q45tech]

800 MHz cellular [2" 1/4 wavelength] or 1800 GSM/1900 MHz PCS [1" 1/4 wavelength].

"Motorola, Inc., in comments filed with the FCC, has expressed the opinion that proper installation of a vehicle-mounted antenna to maximize the shielding effect is an effective way of limiting exposure. Motorola and other companies have recommended antenna installation either in the center of the roof or the center of the trunk. In response to concerns expressed over the commonly-used rear-window mounted cellular antennas, Motorola has recommended a minimum separation distance of 30-60 cm (1 -2 feet) to minimize exposure to vehicle occupants resulting from antenna mismatch for this type of antenna installation. "

The major problem is coax cable attenuation from transmitter to antenna which for RG58 can be 3.3 db/10 foot.

An inside antenna may be no better than holding a portable to ones ear. The major problem is the line of sight to cell tower......blocked by metal.

http://iwce-mrt.com/ar/radio_u...prove/

You might not like this one:http://www.mobilecomms-technol....html

Once had 6 antenna on my company car never got a ticket.

[szh]

An inside antenna may be no better than holding a portable to ones ear. The major problem is the line of sight to cell tower......blocked by metal.

Yes - agreed!! We (my company) do a lot of cellular work and we do drive-testing of our customers equipment for vehicle tracking and radio certifications for our technology. The inside antennas don't make a difference.

Once had 6 antenna on my company car never got a ticket.

Tougher problem nowadays!

We have gotten familiar with the CHP officers between San Jose and Sacramento. This is our drive test cycle - they frequently see one of our employees (his personal car that he uses every day to/fro home - we compensate him for this testing) with 6 to 10 cellular magnetic mount antennas on his car and load of equipment in his trunk. We built a special platform that holds about six laptops (controlling the radios) and assorted power supplies, etc. Basically, a cellular test system on wheels!

Z

[szh]

with 6 to 10 cellular magnetic mount antennas on his car ...

I forgot to mention: these antennas need to be more than 8 to 10 inches apart (these are the 3dB gain magnetic mounts available from Radio Shack). Else they start affecting each others performance!

Z

[BigBodyQ45]

Well if I only plan on using 1.. what would I get? Where would I put it? Good brand? Model? Do they make good ones that are more flush looking like XM radio style or a stubbier one. I just dont want one that looks like a curly pig tail unless thats all that really works.

Thanks again,Dave

By the way Q45TECH: That antenna you posted just isnt the style I am looking for...


Modified by BigBodyQ45 at 11:11 PM 10/11/2004

[Q45tech]

In a former life did a lot a testing for AMPS [Motorolas first hand held in early 80's]. Had cellular 60 watt mobile phone at 860 MHz in Puerto Rico in 1986. Mobile repeater to use the full power when away from car with hand held Motorola brick:http://motoinfo.motorola.com/m...t.asp

Had 150Mhz mobile phone, 2 -450 mobile phones and 800 Mhz trunking pedecessor to cellular phone and and 800 Mhz trunking radio plus 150 mhz police and 450 Mhz police transceivers all in the same 1981, & 83, & 85 2 door brown Impalas.Changed batteries and alternators every 6 months.

My specialty is above 1GHz antenna especially 2-38 Ghz.

Magnetic mounts [?] I love to drill round holes in top and rear fenders and trunk.

The major problem with inside antenna is doppler shift and selective fading at highway speed. Lots of Secret service and DEA have hidden under rear deck tuned cavity antenna but they are at 410-420 Mhz.

How about something decorative and eye catching:http://www.northcountryradio.c...4.gifhttp://www.northcountryradio.c...e.htm

For a frequency of 850 Mhz and above the diameter of the top disc would be 0.17lamda or ~~1.5"..............you could cover it with a tiny plastic Xmas tree.

[szh]

In a former life did a lot a testing for AMPS [Motorolas first hand held in early 80's].

Hmmm ... want another job in the cellular industry? We are always looking for good people!

Magnetic mounts [?] I love to drill round holes in top and rear fenders and trunk.

We use magnetic mounts because it is the employee's personal car! Don't wanna drill permanent holes in it and it does not always need the multiple antennas when we are not actually doing testing (when he drives to/fro home)!

Lots of Secret service and DEA have hidden under rear deck tuned cavity antenna but they are at 410-420 Mhz.

We use similar hidden antennas for our car theft recovery systems ... at cellular frequencies (850Mhz). These do have some losses, but are still very usable with our transmission technology, which works down to about -105dbM RSSI.

How about something decorative and eye catching:http://www.northcountryradio.c...4.gifhttp://www.northcountryradio.c...e.htm

For a frequency of 850 Mhz and above the diameter of the top disc would be 0.17lamda or ~~1.5"..............you could cover it with a tiny plastic Xmas tree.

ROFL!! Pretty funny!

Z

[BigBodyQ45]

That thing is hidious. Well, I see vans with all of those things all over it when I go to meetings or trainings at my corporate office. I think they are tower techs or something. I work in retail for Cingular and only really about the handsets. Damn, 60 watt phone? What are the current ones, .6 right? I rememer them being anolog only 3 watt and those were powerhouses. Well other that that, any idea on a realistic everyday use GSM aplication that I can use on my Q? It will either be on 850 or 1900.

[szh]

Damn, 60 watt phone? What are the current ones, .6 right?

For older AMPS phones, that is the maximum (although the base stations will send out power level commands to reduce handset transmission power - based on distance from the tower). CDMA and GSM are different power - also have more tightly controlled power levels and steps than AMPS.

Quote »Well other that that, any idea on a realistic everyday use GSM aplication that I can use on my Q? It will either be on 850 or 1900.[/quote]850-only GSM handsets are not available that I know of ... most US GSM handsets are 1900 or dual-band 850/1900 (will become more common as Cingular and AT&T complete their 850 MHz transition from TDMA in the future.) I would also think that most available GSM phones will become tri-band soon enough (850, 1900 and 1800 for Europe).

What did you mean by "GSM Application" though? I am not sure whether you meant just a handset or more than that.

Z

[BigBodyQ45]

I figured that antenna wise they have some that work better depending on what MHz it was running on. Most of our phones are dual band GSM. 850 and 1900. That is really all that is used in the states for GSM. Very few of our phones are tri band and some are quad band. I am just looking for a average consumer can antenna that will hook up with my hard wired car kit that uses a FME (male)external antenna connection with a TNC (female) adapter if needed. I was hoping someone knew what I need to buy to get this up and running before I go into radio shack and just pick up some POS thing that does not work. Any advice would be great.

Thanks again,Dave
Modified by BigBodyQ45 at 3:29 PM 10/14/2004

[szh]

For what it is worth, the Radio Shack cellular car antennas are very decent and easy to find (lots of Radio Shacks around!) We use their 3dB gain magnetic mounts to avoid drilling holes. The connectors are good with low reflectance (i.e., more power gets to the transmitted antenna signal), etc.

There are other sources, of course! If you really want some esoteric designs, then let me know and I will have our RF folks get me some of their catalogs and sites for antenna sources and I will pass them along.

Z

[BigBodyQ45]

Is there anything I can get off of ebay that I can search for?

[IvoryJ30t]

850-only GSM handsets are not available that I know of ... most US GSM handsets are 1900 or dual-band 850/1900 (will become more common as Cingular and AT&T complete their 850 MHz transition from TDMA in the future.) I would also think that most available GSM phones will become tri-band soon enough (850, 1900 and 1800 for Europe).

my current ATT phone is tri band gsm. [850, 1800, 1900 MHz]

[szh]

my current ATT phone is tri band gsm. [850, 1800, 1900 MHz]

Cool! It is happening sooner than I thought ... apparently, most of the carriers who have roaming deals in Europe have introduced loads of tri-band phones. Some are even quad-band, from what I see at the web sites.

Z

[IvoryJ30t]

i was at the ATT store the other day, and saw about 3 or 4 quad band phones.

[szh]

Is there anything I can get off of ebay that I can search for?

This one is similar to the Radio Shack ones.

Avoid this type (not to mention it is in Australia) ... it is 850Mhz only!

This might be a bit overkill Needs a fixed location ... not as useful for a car! But has 14dB gain!

I don't really see any unusual esoteric ones. Some of the ones shown are 0dB gain, and these may be just fine for your needs (to get the antenna outside the car is sufficient for most people.)

Z

[BigBodyQ45]

The first looks OK but isnt it one of those ones that just go out your window and goes on the roof. I want a permanant one that you see no wires and goes on the back window somewhere and if possible one with out the curly thing.

[BigBodyQ45]

Are those repeater antennas BS?

http://bluetoothking.com/Merch...FR904

http://bluetoothking.com/Merch...F-905

http://www.cellularking.com/Me...ILSON

http://www.cellularking.com/Me...ILSON

how about those?
Modified by BigBodyQ45 at 12:26 PM 10/21/2004

[szh]

Are those repeater antennas BS?

how about those?

It is always better to use hard wire connections - they have less power reflectance, and less loss, at the interface "through" the glass. They are better than nothing, but it would be better to use the wired ones.

Of course, your window tinting - particularly if metallic - will cause a problem. You would need to cut the tint at the right spot on the glass for the adhesive, etc., and I would be concerned about the ground plane being "changed" as a result of the metallic tint, particularly if it touches the antenna. Probably better for you to use hard-wired antennas!

The first two above seemed to have wiring that fits through around the edge of the glass - these will be better than the glass mounted ones that have an internal adhesive mounted pickup (like the original 90-93 Infiniti Q ones!) Note, of course, that the Wilson looks like a half-wave antenna, so the gain is higher to begin with (though not mentioned.)

I suspect that these four (if the first two are wired) are probably similar in overall performance. Although the specs do not mention the gain ... all four are likely to be better than the handset antenna inside the car.

Z

[BigBodyQ45]

The cheep 5 db antennas on ebay are BS too, right? My tint is very light reflective? Are all reflective tints metalic? I do like the look of that first one a lot but cant find much info on it.

Here it says it has a 2db gain:http://www.altwireless.com/Mer...tTERK
Modified by BigBodyQ45 at 2:12 AM 10/22/2004