RFB,
You have spent many paragraphs trying to convince me that there is a difference between a transmitter and a repeater by stressing the difference in the hardware when my points were focused on the result rather than the implementation. If it will help you understand this then we can call them both intentional radiators.
My contribution to this discussion was with regard to the interference patterns produced by multiple "intentional radiators" operating in proximity on the same frequency. How does it matter whether they are called repeaters or transmitters when the end result in terms of radiated fields is the same?
Does a "repeater" produce a radiated field which is different from that of a "transmitter"? Can this difference be observed at a distance by examining the radiated field? Do not both radiate signals which might overlap and interact?
I wrote How is the use of repeaters different from using multiple transmitters? to which you replied The main difference is that your not using multiple transmitters. Your using one transmitter feeding a coax which provides the signal to the repeaters. And of course they are going to overlap. You get that either method you choose to use.
It appears we agree on the potential interaction situation which was my point but I wanted to make it clear that this will happen with "repeaters" as well as with "transmitters" and not leave the impression that somehow a repeater is different from a transmitter with regard to signal interaction patterns.
Neil
The Repeater Circuit linked by MRAM has been in my sights for a long time, I like the concept and the variable power to the final. In the same document is a circuit for a full 100mW transmitter and a 5-Watt transmitter with variable output power, which would be good for carrier current.
My remark about "the mission of transmission" was not intended to contribute to the discussion about defining a transmitter, but was my enjoyment over the play on words.
"I managed to find the schematic and description of the BCB repeater circuit."
Yep that is it. It can be found in the Earnest G Wilson PDF located within the library resources.
Very simple, very effective and if one fails, it does not knock out everything after that.
This approach keeps the heart of the system where it belongs...at the source point instead of being scattered.
"You have spent many paragraphs trying to convince me that there is a difference between a transmitter and a repeater by stressing the difference in the hardware "
I have not spent any time trying to convince you of anything at all. I am merely reflecting what I was taught and continue to abide by in what the differences are between these two devices, and what they form when combined. Simple as that. It would seem that it is YOU who is trying to convince otherwise.
But as I stated earlier, everyone has their own interpretations and those interpretations run as many as there are people on the planet. Quite diverse if you ask me. However diverse the interpretations are from one individual to another, the fact remains that there is definitive definition and description of the difference as noted in many publications by credited authors.
Semantics....that's kin to political correctness, something in abundance which is not only bending the definition rules to everything, but also causing a lot of confusion across the board, and I do not follow political correctness or semantics. I call it for what it is as it is. I only go by what I was taught and adhere to all these years, which has done good for me. For everyone else, it is up to each to define their own parameters as to how to interpret something, even if there is overwhelming documentation that proves different from their conclusion.
One thing we can all agree on is the discussion has brought forth a good amount of information for people to research and find the best solution for their situation. Now they have a choice...where as before..it all began with a question of "how to".
There ya go...enough brain bucket food to ponder on and find the way to light at the end of the tunnel.
RFB
"My remark about "the mission of transmission" was not intended to contribute to the discussion about defining a transmitter, but was my enjoyment over the play on words."
One cannot argue with the attempt to have some fun with words. It can be quite amusing as well as informative. Sometimes you have to reel in the inquiring minds with a bit of humor first before the attention span can focus on the subject at hand.
However, there is the other side of the coin. Just as wording can be toyed with for fun, it can also be used to confuse and divert attention away from what is. That happens all the time when a politician speaks behind the podium and teleprompters.
The key is to know the difference and not allow yourself to be duped into what is clearly a diversion tactic.
RFB
Thank you, sir. I really aapreciate it.
Quoting RFB "Just as wording can be toyed with for fun, it can also be used to confuse and divert attention away from what is.
Yes, and that has happened here on the subject of interaction. My point is simply this: It makes no difference whether the source is a transmitter or a repeater in terms of nulls or interactions produced by multiple RF radiating sources.
The only time I alluded to repeaters being transmitters was when I posted Yes you are. The "repeaters" radiate signals equivalent to those of transmitters". The point of contention appears to be my use of "Yes you are" in reply to your statement but if you take this in the context of the rest of my quote above you will see that I never claimed repeaters are transmitters, only that they produce the same signals.
I know the difference between transmitters and repeaters having designed and constructed both. I admit I should have been more careful and not abbreviated my "Yes you are" comment but I did attempt to clarify my point by stating the context in the rest of my statement. Sorry for the confusion.
Neil
Thanks MRAM1500 for the link to the BCB repeater article. This is a class A amplifier so the efficiency will be at best 50%. Since efficiency depends on several factors such as the load impedance I simulated the circuit to gain an estimate of the efficiency.
I used a load of 30 ohms in series with 30 pF to simulate a 3 meter antenna system and measured the power delivered to the 30 ohm resistance.
A 1600 kHz sine input was used and the amplitude was adjusted to give a collector voltage swing of half VCC to allow for increases with modulation without saturation. The tank circuit was tuned to resonance.
The simulation gave an input power of 73 mW and and output power of 236 microwatts for an efficiency of 0.32%.
If anyone is considering building this circuit these data could be helpful.
Neil
"I did attempt to clarify my point by stating the context in the rest of my statement. Sorry for the confusion."
Not necessary to apologize for the confusion on my part in your clarification of your point. Its my fault on that.
It's a shame..we can send men to the moon and probes to mars but we cannot come up with a sure fire way to ensure non-confusion via simple text written on a forum!
In any event, yes both produce a signal and radiate said signal. One can do it by itself, while the other requires being fed a signal to radiate. But in the end, they perform the same act..radiating a signal.
In regards to the repeater amplifier posted from the EGW pdf on CC Techniques, it is cheap, easily constructed with common components that are easily obtainable, and works incredibly well. It's efficiency may not be the best, but that can be changed a bit. As it is, and for the purpose and power levels involved, the low efficiency should really not be of any huge concern or be any reason for not experimenting with or put to actual use.
Plus the design is what.....25 years old thereabouts? No doubt a better active element could be used in the base design to improve the efficiency.
Its a good starting reference point to build a better mouse trap per say.
RFB
RFB wrote "Its a good starting reference point to build a better mouse trap per say."
I agree.
Neil