After many hours of experimenting and way too much money spent I have my T2 working flawlessly using the IRF6. I do not use any of the other add-on modules, power sensors or rs232 etc etc.

I am amazed that anyone has managed to get an IRF6 and T2 to work from the box properly.

IMHO there are two main flaws with the design. The T2 does not transmit with sufficient power, but I accept that RTI are somewhat handicapped by law.

What is inexcusable though is the receiver/antenna setup. There just is not enough gain as standard.

By addressing both problems I now have a great setup.

The T2 mod is for the brave or foolhardy only as it requires soldering of a single component between pins on the Lynx transmit module. I'm not going to give details, just read the Linx module data sheet.

For anyone concerned, its difficult to see how this mod boosts the transmit power beyond the legal limit as the IRF6 with the standard antenna would still not work when the remote was more than about 10 feet from the IRF6 !!

The receiver change requires nothing more than replacing the standard (supposedly high gain .. a sick joke ? ) antenna with a wideband active antenna. This uses an integral electronic wideband RF amplifier to boost the gain. I bought it from an amateur radio store.

I cant say whether the IRF6 antenna fix is sufficient on its own. I havent tried this and have no intention of doing so.

I'm no expert on antennas but the standard IRF6 whip antenna doesnt even seem to be the correct length for the carrier frequency. I'm happy to stand corrected here.

I know someone has suggested using a simple solid core wire for the antenna but this was just too prone to interference for me. It just wasnt reliable.

I am now able to have the antenna in another room from the remote. There is a single celcon/breeze block wall between the two. The remote works at any angle and from any position in the room, 100% of the time.

I know this post perhaps does not reflect well on the T2/IRF6 system and may scare people off, but I think its only fair to warn people that they should either be comfortable making mods and spending lots of time getting it working, or get assurances from their supplier/installer that the kit can go back if it doesnt work.

For me at least I'm happy I spent the time fixing it.

I originated the first mods over 3-1/2 years ago and have worked many a frustrating hour since that time to further improve the performance. So I can really understand your pain.


Transmit Power has never been the T2's problem as the transmitter is already jacked up as high as legally possible. The fault is in the incompatibility of the antenna itself as it relates to the frequency used. This mistake is of the self-canceling variety.


I am glad to see that you got your remote going the way you want it to :)


Actually you don’t solder anything "between" any of the pins, I never found that direction effectual enough for my customers application. The problem is rooted in the incompatibility of the antenna to operate properly at 418MHz. But you are right about the “brave or foolhardy only” Part. This is a qualified personnel only kind of operation.


Once again this is an incompatibility problem with both the transmit and receive antennas, (mostly the receiving antenna and related components)

The mods I now do (Gen 3) have netted 100% reception within some (but not all) whole home multiple floor control situations, I am now working on a new "megantenna" which I believe will extend the reception even further. I am in the process of compiling an actual measured distance evaluation chart comparing the different components effective ranges in (feet) line of site(stock versus modified)tests. I will put up a link to this when I am done.

I agree with you that it is unfortunate that this problem even exists at all, but you can rest assured that things will be changing in the RTI camp for the better.

For those that do not have the means to modify their IRF-6 properly or have a modified IRF-6 that was not done properly I can do (or correct as the case may be) the upgrade for you. Email me for more information.

I cannot at this time however, offer an upgrade for the T2 until it is shown that my T2 modification actually does not exceed FCC regulations.


David

A couple of points I want pick up on.

I think we are saying much the same. I found that increasing the T2s output power to the maximum possible electrically, according to the Linx spec, was not THE solution. It helped but no where near enough. IIRC, theoretically the T2s output power as standard is about 6db below the absolute max rating. And I mean the max electrically, not legally.

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 ? 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 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.

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 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 cant 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.

There will obviously be loads of other off the shelf antennas that will help. This one just happens to work for me.

The only downside to my solution, as far as I can see is the increased size of the antenna. Its not something you are going to be able to hide easily. Fortunately for me the antenna is inside my garage, the T2 is used in the room next door.

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, atleast where RF operation is concerned.

No one else to my knowledge has done the testing; my information comes from upper management at RTI regarding the output


I was told that it is cranked up pretty far already.


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 “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.


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.



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.

I admit my approach is synonymous with a sledge hammer, in that I have increased tx power and receiver gain, thereby masking the woeful inefficiency of the standard tx/rx design.

I should clarify that the T2 mod I refer to does not relate to the 'T' attenuator, which as you say is not actually in use.

These are the only website links for the D505 I could find: http://www.wsplc.com and [Link: ozgear.com.au]

I'm not sure if this is the main site but I cant actually see the D505 ! [Link: rfparts.com]


Your concerns about time to setup and interference may well be valid, I did have to play with the siting of the antenna to avoid interference from my plasma. Although once I realised the Plasma was the problem I just had to place the antenna sufficiently far enough away from it.

I can certainly see why you as an installer need something that works for every environment. Just a pity RTI didnt see this as an essential requirement.

It'll be interesting to see how the T2+ and new IRF6 fare.

RTI has already incorporated part of my IRF-6 Mod in their new product. I want to go on further to say that I once had one of my techs swap out the transmit and receive chips for 900 Mhz models while using the stock antenna assembly, but it did not help. You need to keep in mind that NASA uses extremely low power transmitters on their space probes, far less than what the T2 puts out, but they are communicating over vast distances. The reason they can do this has everything to do with the engineering that went into the transmit and receive antennas.

Another thing to consider is that increasing the output, while probably pushing the remote beyond legal limits, also uses considerably more battery power, which means that not only do you have to re-charge more, but also, you will be replacing batteries more often.

I am almost finished with a web page that has a chart showing the actual field-tested ranges of the IRF-6 and T2 with and without modifications. Field test meaning, I took the whole mess out into a field with a tape measure to see what the actual ranges were in feet.

I will put up a link as soon as I am done.