NPC/Swing Mod for Galaxy 93T ??

[Wire Weasel]

Can't find any info on the webs. Many of the Medium Power Galaxy's do the easy Swing Mod by adding the Diode on R238. - My 93T has an R238 in the same general area as the other Galaxy's but not in exactly the same place. Is a different Board than say a 99V. Does anyone know if you can do the mod on the 93T's R238 or otherwise know the Swing Mod for this radio?

Also trying to see more power out. Has a single 2290 pill for a final. Factory specs state 50W max p.e.p. for this rig and that is exactly what mine is doing ...... but there must be some limiting going on. Specs on a 2290 is 70W and you can usually get 80 or 90 out of one. - Anyone know how to get my 93T to do more than 50 watts ??

Thanks !!

 

[sonoma]

this radio has the 690010z board in it. R264 in this radio is the same as the R238 you are asking about.
the npc/rc mod is the same on this radio as all the others out. just add a diode and cap at the same location you do on others and pull the center pin for the mirror board and add the wire jumper to the location you removed the pin. this mod is pretty straight forward from on radio to another.

cbtricks has all the alignment procedures so you can peak it out.

 

[LeapFrog]

For the higher power radios such as the RCI 2970DX, Galaxy 93T, and other radios a 15K resistor may be required across the gray wires of the MD-1. These radios may require 10-Watts minimum dead carrier for the modulator to work properly

From: here.

I don't think they changed the board much, I am willing to bet money that radio could be "NPC or swing modded", buy the Top-Gun MD-1 Modulator if you want a guaranteed solution, other-wise I think the modification you want, is possible on a 93T.

Edit: Thanks Sonoma, I just saw your post.

 

[sonoma]

I would put a MD-1 myself since it has a way to turn it off if you have too much audio. I started using them on my radios a couple years ago.most of the time you can find one for 12.00 shipped to the house.

 

[9C1Driver]

That or the SP1-A. http://www.topguntec.com/tgt_sp_1a.htm

 

[LeapFrog]

That or the SP1-A. http://www.topguntec.com/tgt_sp_1a.htm

9C1Driver, that is a good suggestion for someone wanting average modulation percentages increased, but, based on the original post, I think Wire Weasel is looking to go beyond 100% modulation.

 

[sp5it]

Use 100Ohm resistor and 1n4148 diode parallel to C233.
Mike

 

[dnolan747]

NPC-RC Modification for 6900xxx Type Boards

OK guys and gals a little studying needs to be done here but if you havent noticed the 6900xxx board found in say the galaxy 94hp and the 069610Z board of the Galaxy 949/959 are basically the same even part numbers are the same,, so I will do only one to save time……

Parts needed 1- 1n4001 diode
2- 100ohm resistor
3- 6 inch piece of 18guage stranded wire


Step 1- Take the diode and resistor and solder the banded end of the diode to the resistor…Then fold the other end of the resistor down to form kinda like a hair pin….(see attachment 1)

Step 2- C233 needs to be removed from the board and saved for use in another step (see attachment 2)

Step 3- Now take diode resistor combo and place where C233 was with diode lead in the hole facing the front of the radio and the resistor lead in the hole facing the rear of the radio.. Now solder diode resistor combo in place then take the capacitor you took out of C233 and solder to the diode resistor combo on the solder side of the board .. Make sure the cap if as flat as possible so it doesn’t interfere with the top case lid..

Step 3- Look near the final you will see a Bias board on SSB radios and a set of jumpers on AM/FM only radios, this is where TP7,8,and 9 are,, on this board TP8 needs to be removed,, on SSB radios there is a clip for TP8, remove the clip then replace the bias board…. ON AM/FM only radios you need to remove the jumpers from TP8 and lift out of the hole and then solder together so now the jumper goes from TP7 to TP9 bypassing TP8.…(see attachment 3)

Step 4- Take your piece of 18 gauge wire and strip 1/8” off each end and tin with solder,, now where you removed the clip or jumpers from TP8 solder one end of the wire to this point on the solder side of the board,, now solder the other end to the 12v rail of the emitter of Q54 (see attachment 4)

Step 5- R276 needs to be disabled this is the AMC for this radio and by disabling this resistor on SSB radios the SSB should not be affected,,, now you need to find Q57 and 39, if they are there and unmolested leave them alone and if they are missing replace them,, these are components of the AMC also but will affect SSB….(see attachment 5)

Step 6- The power needs to be retuned now.. The high power needs to be set first.. Put variable knob on the high setting now inside the radio look for VR14 set this for 7 watts on low power radios and for high power radios set for 25 watts.

Step 7- Put the power variable to the lowest setting,,, now adjust VR18 for 2 watts for low power radios and 5 watts if you desire for high power radios,, go back and check high power settings to make sure they are correct, if not, tune accordingly….

Step 8- For the driver check bias as per the Galaxy 98VHP service manual on the main CBT website…… Now for the final since the clip for TP8 is gone you cant check final bias as per the service manual so what you need to do is disconnect the red wire and place the meter leads in series with the wire and the spot where TP8 clip use to be…. (thanks to Rickey aka couch potatoe for the correct procedure on this step)

I would highly recommend using non conductive tuning sticks for steps 6 thru 8.…..





This is for educational purposes only,, I am not responsible if you burn your radio or mess it up in any way……

Thanks to Billy Dean Ward aka CB Doctor for all the help and knowledge for this modification……



This is my post from Billy's old forum RF Study Group,, I know this post is a few months old but i hope it helps


Dean

 

[sonoma]

Hey Dean you went into a lot of work to put this npc mod together. good job buddy. hope some one likes this since you did all the work for them.

 

[dnolan747]

Thanks Sonoma!! I have spent a great deal of time on this modification and love the results that i come out with when i do it... A lot of people dislike this mod but if you do it correctly and tune the radio just right it is beautiful... I also have the mod saved for all other boards and i believe i have it for the 148 also,, I had posted them on Billy's forum but since he is gone (RIP buddy) all of that information has been lost so when i saw this post i decided to place it here.....



Dean

 

[Onelasttime]

Can't find any info on the webs. Many of the Medium Power Galaxy's do the easy Swing Mod by adding the Diode on R238. - My 93T has an R238 in the same general area as the other Galaxy's but not in exactly the same place. Is a different Board than say a 99V. Does anyone know ack if you can do the mod on the 93T's R238 or otherwise know the Swing Mod for this radio?

Also trying to see more power out. Has a single 2290 pill for a final. Factory specs state 50W max p.e.p. for this rig and that is exactly what mine is doing ...... but there must be some limiting going on. Specs on a 2290 is 70W and you can usually get 80 or 90 out of one. - Anyone know how to get my 93T to do more than 50 watts ??

Thanks !!

I think one needs to go school if you think there is some "limiting" going on. LOL II guess Maxwell and Tesla had it all wrong! LOL On what planet do you get 100% effeciency out of a Class AB or C rf amp? LOL Is it genetic, closed head wound or just a lack of understanding with you guys? AM is only the single worst mode to attempt to get full power out of a device on.

Let me guess you want to to dead key 1/4 watt and swing to 70 watts or 100 watts with a single 2SC2290? I need a cup of coffee and some asprin after reading this.

Few hints for using Google instead of trying to find the NPC mode for this radio based on model number which I am sure is out their look up the board number!!! They can stick any model number they want on a radio it is the guts under the hood that matter not the model number!