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toolbox
Posted on Sunday, September 15, 2002 - 12:41 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Can any one tell me how to mod a connex 3300 out? It does'nt have to be a wild mod, just something to help it out some. get the most swing
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Sintronic_Cpu
Posted on Sunday, September 15, 2002 - 3:11 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Go to radio shack and pick up a 1N4001 Diode, about $1.50 for a 2 pack. Clip R-238 and solder the diode between the clipped connections... the banded end of the diode goes toward the board. If you need anymore information on this mod, let me know, I'll email you what I have. This mod lets you set your carrier anywhere you want and swing 100% Full Radio peak. (also r238 is located infront of the AM High power pot, VR13)

Example: before the mod, if you have a 1 watt dead key, you'll only swing to about 8 watts. If you have a 7 watt dead key you'll swing over 20 watts.

After the mod, you can key 1 watt and swing to the full 20+ watts!

I've done this to a 3300 Connex, also the Galaxy mobiles with the 3600 board. Make sure you turn up the mod pot (VR14)or clip one end of R249 to get full swing... but clipping sometimes gets garbly, so turning up VR14 usually does a better job.
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toolbox
Posted on Monday, September 23, 2002 - 9:24 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

can you email me what u have ?thanks for any info
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Sintronic_Cpu
Posted on Monday, September 23, 2002 - 10:27 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Super tune: Solder a 68pf capacitor from the antenna end of L31to board ground (chassis ground may work, also). Change R174 and 187 from 10k units to 2.2k units. Peak L31, L33, L42, L51, and L52 for best swing, using a loud, steady "aaah" sound in the mic. Set carrier control pots as normal for high and low power levels. For louder, cleaner talkback, solder a 330k-2.2Meg-ohm resistor from pin 4 of the audio chip to pin 1of the 4558 IC (IC4). Values under 330k may generate noise on receive.
SUPER SWING MODIFICATION
1. Cut one side of R238.
2. Add a 1N4001 diode to the cut end. Banded-end of diode toward pc board.

MODULATION LIMITER BYPASS
1. Remove R249.

EXCESSIVE NOISE IN RECEIVE
1. Find J103 towards the front of the radio in the center.
2. Flip the radio over and locate the pins for J103.
3. From the right as you are looking at the bottom of the board, count over to pins 7 and 8. Are they shorted? If so, your noise blanker
circuit is disabled. Remove this short and your noise blanker will now work. Many DX radios left the factory this way. I do not know why.

Clarifier Mod
Remove R141
Remove D38
Solder bridge J106 pin 54 to 8 volts


Clicked on your name, but you aren't registered (couldn't get your email)... this is most of what I have, I have some pictures somewhere too... these mods will work on all Connex, Galaxy, Northstar, and every other radio with the EPT3600 board! But the top supertune is not neccisary if you put the diode between R238.
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jyd
Posted on Tuesday, September 24, 2002 - 5:42 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

i would not recomend a super duper tune
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Insider
Posted on Tuesday, September 24, 2002 - 6:26 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

If you do the NPC mod (the diode in line with R238) I don't think you'd want to bypass the modulation limiter.
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ss8541
Posted on Tuesday, September 24, 2002 - 11:54 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

oops.... it should say that the positive peaks flattop, not the negative peaks.
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Sintronic_Cpu
Posted on Wednesday, September 25, 2002 - 12:14 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I'm not disagreeing with anyone, but I'm having an informational conflict here.

There is a post in the subsciber preview section on the NPC/RC mod for the Voyager VR9000 (which also employs the EPT3600 board). This is the bottom part of step three:

Disable On Board Automatic Modulation Control

With the radio component side up, knobs facing you

Look near the center and REAR of PCB

Locate resistor R249 (10K ohms) Color Bands are Brown, Black, Orange

Un-solder one wire leg of the resistor and lift it out of it's mounting hole. This disables the onboard AMC circuit built into the radio circuit. This does NOT mean that your radio does not have an active AMC circuit. The NPC-RC modification IS a modulation modification circuit in itself . It controls both the positive AND negative audio peaks so they don't clip and distort the waveform while still maintaining a very high level of CLEAN modulation.

Not trying to step on anyones toes, or thoughts, I'm just really confused now. When I first got a Galaxy (DX33) clipping R249 did make it distort, but after I put the diode between r238, it was clean and clear.

Recently I purchased a DX99 from Coppers, I did the r238 Mod without clipping it, the audio was still as low as before I did the mod. And I did turn the Mod pot 100% wide open. I would key one watt, and only swing 10, after clipping it, I now swing 25 watts PEP from a 1 watt dead key. It doesn't sound distorted, it's very clear. Someone even recorded me on a memobox and played it back over and over to aggrivate me, sounded A-1, top shelf!

Any ideas? Is that true, does the NPC work in place of the AMC? My audio cleared up on that 33 once I did the NPC.

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ss8541
Posted on Wednesday, September 25, 2002 - 1:04 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

your not stepping on my toes. i see radios everyday with these mods. every radio i see goes on a scope. infact i had a 66 with the diode inserted at r238 and r249 clipped today. from any deadkey the neg and positive peaks flattened just like if tr32 was removed all together. every radio i have seen with this mod does this. same for the 100ohm/silicone diode with limiter removed mod. that is why i say if you want that type of sound just remove the limiter. and i guess i should clarify limiter as tr32 since tr32 still does -some- limiting in am even after r249 is cut. with tr32 gone there is -no- limiting.
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jyd
Posted on Thursday, September 26, 2002 - 11:09 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

i have done these mods,i was impressed by the swing.but the audio did not impress me.i say leave the limiter intacked,turn up the varible.as for a 99 it will sound better than other with the mod.(but)it is built better and with better parts.the are alot of conciderations with diffrent radios