On 02/21/04 05:35, JohnSwindon said...
When you say that the T2 already outputs the max
allowed power, have you measured this ? Its a
reasonable assumption obviously, but I wonder
if anyone has measured it independently of RTI
No one else to my knowledge has done the testing; my information comes from upper management at RTI regarding the output
? I guess it has been tested by the FCC at some
stage. But lets face it, no output at all is within
FCC spec. Is the T2s transmit power closer to
no output than it is to the maximum allowed ?
I was told that it is cranked up pretty far already.
I should have also mentioned that I made the mods
as someone suggested to the IRF-6, changing cable
to mini RG-8 (BTW, A very good cable) But this
made no discernable difference.
That was I. My first mod used PL295 screw on jacks with RG8 cable, which is what the specification for the frequency recommends, but I also found no discernable improvement over RG-6.
The mod that makes the biggest difference to the
IRF-6 IMHO is not a mod at all. It merely requires
you to throw the standard whip aerial away (The
best thing for it) and replace it with an actively
amplified aerial. No dismantling, no soldering,
no crimping, no cutting, infact no change at all
to the IRF-6 or the antenna feed cable attached
to the IRF-6. I tried a multitude of standard
antenna design/configurations.
The “whip” antenna is actually called a “rubber duck” and is widely used on portable CB radios and the like, but once again it is the wrong kind of wire. I as well as many others have tried all sorts of amplifiers and antenna combinations, but what I am doing now is by far the best solution, I don’t know about your experience but I have found in some instances that amplifiers often amplify problem signals, the same is true with local off air HDTV reception.
The antenna I now use cost about GBP70.00, I'm
sure you could get it considerably cheaper if
you shop around. For reference it is the Dai-ichi
Supervoice D505C aerial. The only thing you need
to add to this is a PL259/BNC adapter and a 12v
DC power supply. I can’t remember the spec but
the gain is adjustable upto 20db and the frequency
range is ???hz upto 1500MHz and of course its
50ohms as required by the Linx receiver module.
I have not been able to find any information on the antenna system you describe above?
Do you have an http:// link for this product? I would like to see what its about.
I think it is great that you have found a solution for your application, but for me as an installer it is better to have a product that I just walk in an install without any conflicts like where to put big antennas. The mods I do (except for the BNC Jack on the IRF-6), are not visible on the outside of the equipment, which I really like because the whole thing installs easily. In most applications I just stick the antenna right on the IRF-6 and it works fine. I areas where there is more interference I go ahead and modify the T2 also.
The RG-194 cable is the main problem, it never should have been used to begin with, further, stranded cable of any type is not suitable for 418MHz, you have to use solid copper. Further still, the Linx spatch antenna is another product that is unsuitable for the application, despite what the specs say. By the way, the specs say that the transmit leg should not be farther than .25 from the input leg of the splatch. The T2 setup has this of f by a ½” or so not including the little pad circuit in between with the 2 -0 ohm test resisters in line.
Its not difficult to see why RTI distribute through
strictly controlled supply channels. This is not
a product that could be supplied direct to the
home market IMHO, at least where RF operation is
concerned.
This remote falls into the Crestron / AMX category of product types and even though most people could eventually figure it out the software engineers at RTI are the same guys who have built the software engines for several popular hi end home automation products, so I guess they just stayed with a sale format that they are already familiar with.
