-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
80% increase in performance?
- Thread starter rabbiporkchop
- Start date
I just figured since Jack's radios had an audio frequency response up to 3k and the other two radios had 300hz clipped off the bottom, and went up to 4K that perhaps that higher response of the other two radios had something to do with being able to hear each other at the greater distance.Don't know how to answer that question.
Last edited:
With my filter set to 20k total bandwidth (10k freq response) the noise floor is -112dbm at 5k total bandwidth (2.5k response) the noise level is -119 dbm if I narrow it down to 1k total bandwidth (500hz response) the floor is at -122dbm. As long at there isn't activity on an adjacent frequency the wider bandwidth rx isn't hurting much. The noise level is broadband and about the same on adjacent bands. The numbers I posted are what I'm currently seeing. I'm not trying to BS you.
Don't know how to answer that question.
I'll give you a hint.
http://www.worldwidedx.com/threads/80-increase-in-performance.218257/#post-595893
That doesn't really explain why Jason's -135dbm receiver could hear my 4 watt signal but he required 25 watts of carrierI'll give you a hint.
http://www.worldwidedx.com/threads/80-increase-in-performance.218257/#post-595893
(6 times the power ) to make the trip to my -113dbm receiver which I never use since the receive sucks compared to other things I have.
Last edited:
It's threads like this one and others started by RBC that have made me a much less frequent visitor to this forum. I don't like to diss anyone, but RBC, why do you continue to make ridiculous claims about your radio's performance without showing us any proof. Sure, I can say that the rigs that I align will talk and hear the best, but so can anyone else. The bottom line on the performance of any radio is what it does on-the-air. You make claims, but as I have said before, please post an A/B comparison of your rig on-the air versus a stocker. You refuse to do this because it will show that your claims are total BS. Your mention of the 2SC 2999 mod as something effective just shows how out-of-touch you are.
I feel sad for you. You are just a troll that wants people to think that you have some sort of understanding about things radio. But to those of us like Capt KW, Bob85, 543Dallas, Sonoma, etal, you are just a joke. Instead of trying to impress us, why don't you just listen and learn.
- 399
I feel sad for you. You are just a troll that wants people to think that you have some sort of understanding about things radio. But to those of us like Capt KW, Bob85, 543Dallas, Sonoma, etal, you are just a joke. Instead of trying to impress us, why don't you just listen and learn.
- 399
I feel sad for you that you think I'm a troll. I've got lots of questions but it's funny none of you want to provide any answers that are relevant. I'm looking for explanations for why my radios do what they do and nobody wants to offer any explanations everybody wants to accuse me of making things up. I don't claim to have any answers although I do know what my radios are capable of doing and I was hoping someone in this forum could provide some explanations for why my radios seem to defy what is commonly accepted as normal.
I asked a question in the above post and you completely ignored it and failed to answer the question so I will ask the question again in a different way.
Jason's -135dbm receiver could hear my 4 watt signal but he required 25 watts of carrier
(6 times the power ) to make the trip to my -113dbm receiver.
when Jason replaced his 25 watt Connex radio with a Barefoot Cobra 29 and I replaced my crappy Uniden PC 76 with a magnum S9 with a -135 dbm receiver I was easily able to hear his 4 watt signal, so if there's really all this atmospheric noise why was I able to hear his 4 watt signal as soon as my noise floor dropped really low with using a different radio? and the same went vice-versa for him when he had a radio connected with a low noise floor listening to my 4 watt radio? I'm simply asking you a question and how is this possible and you seem to be angry at me for posing the question.
I'm not pretending to have any answers I'm simply asking a question how is this possible and you're getting angry at me for asking questions.
RPC -
There are so many factors that go far beyond the differences in receiver noise floor. Time of day, amount of atmospheric noise, condition of antennas, whether or not either of the transmitters had audio processing ... the list goes on and on.
It's a good thing to have the best possible receiver. But on one day you can communicate, and on others you can't. It's all up to Mother Nature.
The problem I have is that it seems whenever you ask a question, you think you already know the answer. The people on the forum provide accurate answers, but you reply and debunk what they have to say if it isn't the answer you wanted to hear. Always stirring up the mud.
- 399
There are so many factors that go far beyond the differences in receiver noise floor. Time of day, amount of atmospheric noise, condition of antennas, whether or not either of the transmitters had audio processing ... the list goes on and on.
It's a good thing to have the best possible receiver. But on one day you can communicate, and on others you can't. It's all up to Mother Nature.
The problem I have is that it seems whenever you ask a question, you think you already know the answer. The people on the forum provide accurate answers, but you reply and debunk what they have to say if it isn't the answer you wanted to hear. Always stirring up the mud.
- 399
A uniden 76 is not really known for its receiver performance. No one is saying that your radio's receiver doesn't work well or that mark can't align a receiver. By design some receivers are better than others when it comes to noise.
Maybe that kind of receiver sensitivity would help you on the dark side of the moon but in real world use that 135 db down doesn't mean much. It sounds impressive but those are ideal test bench conditions with no noise to deal with.
If he tuned the uniden 76 and the magnum s9 so that they were equal on his bench I think you would still find the S9 had a better receiver.
The problem with your real world testing is that you have no data. It's all seat of the pants feeling. You have no way to see the noise floor in dBm with your radios. You could pick up an sdr receiver and use that for a reference. The receiver has to be calibrated to be accurate but you could take your tablet, laptop or whatever to mark and calibrate It to his equipment. That would let you see how low of a noise level you actually have and make a more educated decision on how much the 135db down thing is really worth.
Maybe that kind of receiver sensitivity would help you on the dark side of the moon but in real world use that 135 db down doesn't mean much. It sounds impressive but those are ideal test bench conditions with no noise to deal with.
If he tuned the uniden 76 and the magnum s9 so that they were equal on his bench I think you would still find the S9 had a better receiver.
The problem with your real world testing is that you have no data. It's all seat of the pants feeling. You have no way to see the noise floor in dBm with your radios. You could pick up an sdr receiver and use that for a reference. The receiver has to be calibrated to be accurate but you could take your tablet, laptop or whatever to mark and calibrate It to his equipment. That would let you see how low of a noise level you actually have and make a more educated decision on how much the 135db down thing is really worth.
Not only is real life not the same as bench testing coax connectors, environmental noise, and antenna losses make most modifications marginal at best. On top of that you have the human ear/brain and it's limitations. You run into this in a lot of things from monitor resolution to hi-fi stereo equipment. At some point our human limitations just do not allow us to tell the difference sometimes between a good solid performing middle of the road component and the very finest money can buy.
I have some serious audio gear and I can tell you that very few people can tell the difference between my ok but affordable gear versions my insanely expensive gear it takes a well trained brain to hear the difference. Same thing goes for 1080p and 4K few people can tell the difference if you do not tell them and both grossly exceed what the eye and brain combined can discern if they actually receiving true 1080p and true 4K same thing goes for crazy insane MP camera outside of making enlargements once you get past a certain point the extra is capacity is wasted.
So much is lost in coax and conectors that gaining 1-3 db on the bench is not usually going to make much difference int he real world. If not careful it could hurt more than help.
I do like mod's that make a unit more durable and make them run cooler and cleaner. What is really needed usually is a new circuit design. It would be nice to be able to find components that have better snr, gain on freq., more current, voltage ratings and better heat dissipation but by and large most times this is not possible or is of little use because other design limits.
By and large 98% of the modifications people do to gear is really either worthless or of marginal return. Obviously if repairing a unit it makes sense to upgrade parts where one can but trying to get more power out or more sensitivity on recieve beyond what a standard alignment will do is usually not worth the effort and price if not doing the work yourself.
What really need is a better circuit to work with from the OEM 9 out of 10 times not just better parts!
While it is true that I always upgrade parts when making repairs it is never to get more power output that is just stupid! You never get enough to be worth while always better off just adding an external amp. Reliability, durability cooler operating temps are their own reward! The single bigest liability in a CB radio or black box radio is not the crappy detection diode design but the crappy noisy low fidelity audio IC!!! Your transmit and receive audio all have to go through it. Their are not any better audio ic's that can be dropped in place that are any better either. Even ones that use op amps the turn on voltage often eliminates the swapping of better op amps. The harsh noisy audio is what makes your ear's hurt and what get's on your nerves. Improving everything else is worthless if the audio amp ic or op amps are shit!
I have some serious audio gear and I can tell you that very few people can tell the difference between my ok but affordable gear versions my insanely expensive gear it takes a well trained brain to hear the difference. Same thing goes for 1080p and 4K few people can tell the difference if you do not tell them and both grossly exceed what the eye and brain combined can discern if they actually receiving true 1080p and true 4K same thing goes for crazy insane MP camera outside of making enlargements once you get past a certain point the extra is capacity is wasted.
So much is lost in coax and conectors that gaining 1-3 db on the bench is not usually going to make much difference int he real world. If not careful it could hurt more than help.
I do like mod's that make a unit more durable and make them run cooler and cleaner. What is really needed usually is a new circuit design. It would be nice to be able to find components that have better snr, gain on freq., more current, voltage ratings and better heat dissipation but by and large most times this is not possible or is of little use because other design limits.
By and large 98% of the modifications people do to gear is really either worthless or of marginal return. Obviously if repairing a unit it makes sense to upgrade parts where one can but trying to get more power out or more sensitivity on recieve beyond what a standard alignment will do is usually not worth the effort and price if not doing the work yourself.
What really need is a better circuit to work with from the OEM 9 out of 10 times not just better parts!
While it is true that I always upgrade parts when making repairs it is never to get more power output that is just stupid! You never get enough to be worth while always better off just adding an external amp. Reliability, durability cooler operating temps are their own reward! The single bigest liability in a CB radio or black box radio is not the crappy detection diode design but the crappy noisy low fidelity audio IC!!! Your transmit and receive audio all have to go through it. Their are not any better audio ic's that can be dropped in place that are any better either. Even ones that use op amps the turn on voltage often eliminates the swapping of better op amps. The harsh noisy audio is what makes your ear's hurt and what get's on your nerves. Improving everything else is worthless if the audio amp ic or op amps are shit!
This is hardly scientific but it's a daily occurrence regardless of where I happen to be.
The guy with the HR 2510 in the same parking lot as me had no idea what he was missing out on.
The guy with the HR 2510 in the same parking lot as me had no idea what he was missing out on.
Onelasttime,
hifi is my other hobby,
you don't just need a well trained ears & brain,
like peoples sense of taste & smell not all ears & brains are wired the same,
most are low resolution but not all, no amount of training fixes low res ears,
training does make a huge difference to some people when listening for the subtle differences that most people will never notice even when you point it out to them,
my eyes are too old to see 1080 from 4k at regular viewing distances, close up with magnifying glasses i can tell,
i see colors different to anybody else i know even back in school, if paint on a car is mixed from two colors, or clothing & carpet woven from two colors i see both much to the disgruntlement of my physics tutor who told us eye colour effects who will see a carpet as brown and who sees it as green when it contains even numbers of fibers, it did for everybody except me,
when i spot a two color car & im with two of more people with different color eyes i can get them arguing with each other about what color it is,
the color of their eyes plays a role, a blue eyed person very often see colors different to a brown eyed person,
its funny getting them arguing because each are adamant the other person is color blind,
i can hear a black gate from any other electrolytic or a bright & lean polypropylene in the psu of a single ended tube amp, its night & day to me, music from a black gate comes from a dark & quiet place, i can't explain it any other way,
a V-CAP CuTF coupling cap i can hear almost anywhere in the system providing the rest is high quality & not masking the sound,
the trick for my ears is mixing components with certain qualities to get the balance my ears like.
How do you explain it to folk that don't believe it if their ears & test gear can't see it ?
you can't its impossible but you can get them scratching their heads when you get it right 10x out of 10 in blind tests even when they lie to try tricking you because they hear no change and are 100% convinced you are somehow cheating,
my response is please explain how can you not hear what is obvious to me,
i think having mild aspergers is probably something to do with it but i can't prove it.
hifi is my other hobby,
you don't just need a well trained ears & brain,
like peoples sense of taste & smell not all ears & brains are wired the same,
most are low resolution but not all, no amount of training fixes low res ears,
training does make a huge difference to some people when listening for the subtle differences that most people will never notice even when you point it out to them,
my eyes are too old to see 1080 from 4k at regular viewing distances, close up with magnifying glasses i can tell,
i see colors different to anybody else i know even back in school, if paint on a car is mixed from two colors, or clothing & carpet woven from two colors i see both much to the disgruntlement of my physics tutor who told us eye colour effects who will see a carpet as brown and who sees it as green when it contains even numbers of fibers, it did for everybody except me,
when i spot a two color car & im with two of more people with different color eyes i can get them arguing with each other about what color it is,
the color of their eyes plays a role, a blue eyed person very often see colors different to a brown eyed person,
its funny getting them arguing because each are adamant the other person is color blind,
i can hear a black gate from any other electrolytic or a bright & lean polypropylene in the psu of a single ended tube amp, its night & day to me, music from a black gate comes from a dark & quiet place, i can't explain it any other way,
a V-CAP CuTF coupling cap i can hear almost anywhere in the system providing the rest is high quality & not masking the sound,
the trick for my ears is mixing components with certain qualities to get the balance my ears like.
How do you explain it to folk that don't believe it if their ears & test gear can't see it ?
you can't its impossible but you can get them scratching their heads when you get it right 10x out of 10 in blind tests even when they lie to try tricking you because they hear no change and are 100% convinced you are somehow cheating,
my response is please explain how can you not hear what is obvious to me,
i think having mild aspergers is probably something to do with it but i can't prove it.
- No one is chatting at the moment.
-
-
-
@ BJ radionut:
Discord - A New Way to Chat with Friends & Communities
Discord is the easiest way to communicate over voice, video, and text. Chat, hang out, and stay close with your friends and communities.discord.com
-
-
