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Has anyone been able to duplicate these results?
- Thread starter rabbiporkchop
- Start date
I want to see some of this "testing" also.
Unless your friend has heavily modified the RX stages in that radio (as in changing inductors, capacitors and filtering), it will not perform as well. Again, you're trying to make a radio that's designed to run 28-29.700 mhz operate at 27 mhz. Sure it'll work, but it won't be optimal.
HF rigs have multiple conversion stages for filtering, etc. And they will outperform CB radios AND export radios on 27 mhz. But HF rigs don't belong on CB band, and shouldn't be used there.
Stock radio to stock radio, the CB radio performs better than an export on 27 mhz. If you change out the diodes to the 1N6263 Schottky diodes, on both radios, with a proper alignment, the CB radio still performs better. The 2SC2999 transistor upgrade isn't worth it, the results didn't justify replacement.
Oh, and "El Capo" (Unit_399) is 100% on the money with his post.
~Cheers~
Unless your friend has heavily modified the RX stages in that radio (as in changing inductors, capacitors and filtering), it will not perform as well. Again, you're trying to make a radio that's designed to run 28-29.700 mhz operate at 27 mhz. Sure it'll work, but it won't be optimal.
HF rigs have multiple conversion stages for filtering, etc. And they will outperform CB radios AND export radios on 27 mhz. But HF rigs don't belong on CB band, and shouldn't be used there.
Stock radio to stock radio, the CB radio performs better than an export on 27 mhz. If you change out the diodes to the 1N6263 Schottky diodes, on both radios, with a proper alignment, the CB radio still performs better. The 2SC2999 transistor upgrade isn't worth it, the results didn't justify replacement.
Oh, and "El Capo" (Unit_399) is 100% on the money with his post.
~Cheers~
Excellent response my friend. I find anyone who gives the "I've got a big secret and I'm not letting anybody else in on it" speech is someone I suspect of being a snake oil salesmen.
I guess it kinda makes me think of the King's new clothes. You get what you pay for isn't always the case. The best consumer is an educated/informed one. Happy Memorial Day. 73
The problem with using schottky diodes is the front end overload problems when in close proximity with stronger signals.. For example truckstops.
12 years running coast to coast being told every 10 minutes That "nobody has ever heard me from that distance before"....
What I take for granted, most have never experienced.
With a noise floor that low, I can hear the difference between copper and aluminum antennas while the difference isn't noticeable with a stock radio with noise floor of .3uv..
I will quote the late Russell Clift AB7IF:
Unlike shiny copper, Aluminum on the outside surface is covered with a thin layer of oxide, Al2O3 (sapphire). This insulating surface is a dielectric much thinner than the skin penetration depth for RF at 27 MHZ yet thick enough to allow surface charge to buildup until it breaks down through the very thin layer of sapphire as the local space charge builds up in voltage. In the wind a never ending source of 'static noise' easily heard especially if the receiver is less than a micro-volt in sensitivity. So yes, it can be proven a copper antenna has much less 'static noise' than an aluminum antenna. That is until chemical corrosion coats the copper with oxide. One conclusion being it pays to keep your copper antenna shiny at all times.
If Schottky diodes are potentially causing a front end overload, then the AGC circuit isn't doing its job, either from poor design, or it hasn't been modified to act faster when detecting and receiving strong signals.
Typically, Schottky diodes don't change the dynamic enough to warrant a modification of the AGC circuit in most cases. So if there's a front end overload condition, I suspect a poorly designed AGC circuit or a lack of thereof.
~Cheers~
Typically, Schottky diodes don't change the dynamic enough to warrant a modification of the AGC circuit in most cases. So if there's a front end overload condition, I suspect a poorly designed AGC circuit or a lack of thereof.
~Cheers~
Never had a Schottky create a problem.
However, it has been a mixed bag 'o results when using a 2999 in the 1st RX stage . . .
However, it has been a mixed bag 'o results when using a 2999 in the 1st RX stage . . .
Never had an issue with schottky diodes either. The only issue with front end overload I have is when near another mobile strong enough to turn on my antenna warning light and make my receiver make strange noises.
This radio thing has been going on for a long time. No one is doing anything new or different but some are good at making it seem that way. The best tech in the world can only polish a turd so much. If they are really that talented are they going to be working on super trucker export rigs or would they rather build or design something cool?
This radio thing has been going on for a long time. No one is doing anything new or different but some are good at making it seem that way. The best tech in the world can only polish a turd so much. If they are really that talented are they going to be working on super trucker export rigs or would they rather build or design something cool?
Consistently being able to hear stock Cobra 29's at a distance of 30 miles from trucks with Factory cable and factory antenna systems must mean my receiver is doing what it's supposed to do and if yours cannot do that then it's time to find a new technician.
I hope mark pays you well for your services...or at least returns the favor. I have no technical mumbo-jumbo to add since it will fall on deaf ears. Keep on trucking and trolling.
I used to think so but I believe his name is scott.
I used to think so but I believe his name is scott.
RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
I went out to the garage to put on my chest waders for this thread...lol How do you manage to get rid of all that pesky atmospheric and man made noise that becomes your "noise floor" while driving down the road?