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Magnum s3 schottky and 2n2999 mod
- Thread starter Harley3315
- Start date
Why?
If it's the one with the ERF2030 finals in it, the radio already will do much better in its STOCK form than to do the conversion.
You have 1N60's for Detectors and AGC - even the Quad Op Amp has them ... you already have MC310 PIN diodes too - don't change those either...
Don't use the 2SC2999 - the amount of rework the RF Amp section needs is not worth it - swap in a 2SC1730L instead...
But don't complain about upgrade if you decide to move forward with this. Because many of those parts in there already are idealized for that chassis - it would be a bigger mistake to try and upgrade or change it - you will hate the results and have to switch back - knowing those radios (Galaxy-Class EPT3600 Board in an RF Limited Wrapper) - I can almost guarantee it.
If it's the one with the ERF2030 finals in it, the radio already will do much better in its STOCK form than to do the conversion.
You have 1N60's for Detectors and AGC - even the Quad Op Amp has them ... you already have MC310 PIN diodes too - don't change those either...
Don't use the 2SC2999 - the amount of rework the RF Amp section needs is not worth it - swap in a 2SC1730L instead...
But don't complain about upgrade if you decide to move forward with this. Because many of those parts in there already are idealized for that chassis - it would be a bigger mistake to try and upgrade or change it - you will hate the results and have to switch back - knowing those radios (Galaxy-Class EPT3600 Board in an RF Limited Wrapper) - I can almost guarantee it.
Then you still use have and own the older parts that are better for your radio then to try the upgrade - the AGC and Detector, Pin and Metering - all use the Germanium 1N60s' and or MC310's - giving you the quieter receive and with the Chassis using the L5 open core coil - it would be prudent to just switch to the 1730L for the RF Amps (RX Stage) 1674 - and that is a tight swap for performance in splitting hairs...
You'd be disappointed if you chose to do the Schottky and 2999 swaps - especially after you've had this radio and got used to it's "Hearing" for it'll be "Deaf" after you convert - you really don't need to.
There are two threads both tilted negative towards the conversions but you should know that the comparisons are not clear winners. The conversion process involves making both platforms compatible with each other, and to date, no one has come up with or even needed to design, any sort of platform - they simply require too much support changes and needs to their networks it's not worth converting
The radio has several things going for it right now that make it desirable - and that is; it's in a working condition unmolested Receiver
You'd be disappointed if you chose to do the Schottky and 2999 swaps - especially after you've had this radio and got used to it's "Hearing" for it'll be "Deaf" after you convert - you really don't need to.
There are two threads both tilted negative towards the conversions but you should know that the comparisons are not clear winners. The conversion process involves making both platforms compatible with each other, and to date, no one has come up with or even needed to design, any sort of platform - they simply require too much support changes and needs to their networks it's not worth converting
It can be considered like...
- you're putting in a newer motor in an older car,
- or taking out the older motor and trying to use it in a newer car
- both ways, you are limited to the oldest platform as the weakest link.
- you're putting in a newer motor in an older car,
- or taking out the older motor and trying to use it in a newer car
- both ways, you are limited to the oldest platform as the weakest link.
The radio has several things going for it right now that make it desirable - and that is; it's in a working condition unmolested Receiver
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I got to side with Andy on this one. Out the box, any Magnum S9 (or 3 or 6) has superb receive, in my opinion. That’s especially if you compare it to other radios that were out during that time.
I buy them when I can find them, I like them just that good.
I buy them when I can find them, I like them just that good.
The trouble is in this town the excessive noise from electrical factories and junk electrical lines and Chinese junk electronics is rampant! Alot of my locals are 20 miles out and when I'm home at the base I can hear them all. They run around 200 watts per station I use a 2990 with shottkys at the house. In the truck I'm running the s3 with 102 inch in certain places in town where there isn't noise or something blocking it maybe I can here but mostly not. The input power filtering is excellent in the radio clearly all my power is straight to the battery. Ground was there moved to a seat bolt to see if there was any change. Nada also did the big 3.
Schottky diodes can't help with that, no mods to a radio can because it is RFI being spewed out on the frequencies you're monitoring and received by the antenna. The only way to deal with that is using noise cancellers like the MFJ 1026 which receive the local noise on a separate antenna and feed it in out of phase with the signal from the main antenna to cancel it out.
I don't know where this obsession with schottky diodes has come from but the things that people can claim they do is absolute unadulterated rubbish. I believe Mikes CB did a comparison on Youtube using proper test equipment AND FOUND NO MEASURABLE DIFFERENCE between using the stock diodes and schottky.
Then that's a problem caused by a piss poor antenna system installation. A proper antenna system installation should take most of a day, possibly more than one depending on what you need to remove from the vehicle to do it and if you're making up your own earth straps. It also requires an antenna analyser or VNA to measure the efficiency of your RF ground as you're installing it. Takes me nearly 2 days to do a full installation and I can sit there with a pre-amp on and the engine running with S0 on the meter. You also don't run the negative wire to the battery.
Go to www.k0bg.com and read the sections on common mode current, mounting, grounding and bonding. If your antenna and radio isn't installed like that site tells you to it's not done properly. FYI Alan K0BG wrote the mobile antenna section of the ARRL Antenna Book and knows his stuff. If you have a look in his photo gallery in the hall of shame I suspect there's a few installations which look very familiar.
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Your noise pickup is because the radio is that good.
By your description, the noises in your receiver are normal power line to truck ignition onto air noises from poorly shielded devices leaking into your receiver.
Doing this mod will DEAFEN your radio - to a point where you may not hear your friends at all - even with good quiet conditions. It just is that bad - you are not alone in this...don't waste another thought or your time thinking about the mod, focus more on making better working conditions and providing more for your system
We know what you are up against
If you can drive around WITH THE COAX disconnected at the RADIO - and still hear engine noises, and same noise sources, you have more work to do....
By your description, the noises in your receiver are normal power line to truck ignition onto air noises from poorly shielded devices leaking into your receiver.
Doing this mod will DEAFEN your radio - to a point where you may not hear your friends at all - even with good quiet conditions. It just is that bad - you are not alone in this...don't waste another thought or your time thinking about the mod, focus more on making better working conditions and providing more for your system
We know what you are up against
- - you can hear your friends while on the Base just remember the limitations of the Mobile situation...
- Your closer to the noise sources so by proximity alone in your Mobile
- you get an earful blasting into the truck from those sources...
- If you're running an amp with the pre-amp in it on, you're only making matters worse because the pre-amp is a GENERAL coverage amplifier (READ:UNTUNED) - it picks up everything the antenna gets and amplifies it - including the noise.
If you can drive around WITH THE COAX disconnected at the RADIO - and still hear engine noises, and same noise sources, you have more work to do....
I don't have engine noise I've ground strapped my body to frame engine to frame and so on and so forth its fine if I'm not in town out on the highway or something like that I hear plenty but in town only in "clean" places
Then it is not the fault of your radio, you can recreate the conditions of quiet and noise in their same areas by revisiting them consistently - and if the noise appears then fades as you leave, well the radio isn't the problem. Nor is it the operator.
The noise exists because it's external to the radio - and you can only do so much to reduce the noise - RF gain turned down, Noise Blanker and ANL filtering but then that is not stopping the noises at their sources.
It's frustrating - yes, I have this similar problem too. Just have to relocate to another location.
Now if you try another radio - you may have similar results. That is the only other options we have - changing antennas may help a little for the same radio , but this sounds like a noise problem in the area you live. Not much you can do. Putting in a mod to see if it can help is not always the best option - I just don't want you to become frustrated at trying to find a working solution - it seems you've done your homework.
I'd hate to think that the radio is TOO sensitive to the noises but then that simply means you just turn the RF gain down on the radio - let it do the filter work for you.
Also - use the Clarifier in RX - if the Clarifier has been opened up even better, for then you can "center in" on the station you're talking to. This can help with that noise - you simply line up to each other and talk thru it.
Just some ideas...
The noise exists because it's external to the radio - and you can only do so much to reduce the noise - RF gain turned down, Noise Blanker and ANL filtering but then that is not stopping the noises at their sources.
It's frustrating - yes, I have this similar problem too. Just have to relocate to another location.
Now if you try another radio - you may have similar results. That is the only other options we have - changing antennas may help a little for the same radio , but this sounds like a noise problem in the area you live. Not much you can do. Putting in a mod to see if it can help is not always the best option - I just don't want you to become frustrated at trying to find a working solution - it seems you've done your homework.
I'd hate to think that the radio is TOO sensitive to the noises but then that simply means you just turn the RF gain down on the radio - let it do the filter work for you.
Also - use the Clarifier in RX - if the Clarifier has been opened up even better, for then you can "center in" on the station you're talking to. This can help with that noise - you simply line up to each other and talk thru it.
Just some ideas...
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