RCI 2950 SLIDE MY WAY
|
|
Heavy Swinger Mod
For the RCI-2950
See picture at right
Upgrading The, AM Detector Change D34 & D35 that are 1N60's by ECG583 or SK9975. TALK BACK Modification Kindly explained by John Williams ghost@sccoast.net Well, here goes, the talk back is done by clipping one end of D-78 or you can wire a SPDT switch to switch on and off! I hope this info gets me the way to un-encrypte the RCI bible that you have! Mine seams to be a bit different! By the Way I think the RCI's are the best radio's on the market but I did hear a rumor that they may be closing there doors at the end of the year. I hope it's only a rumor! GOOD MODS. and also from: Bill Eitner kd6tas@earthlink.net A common way to obtain talkback on the 2950 is to lift one leg of the diode marked D-78. Many times, a switch is installed to create a switchable talkback. This is probably not the only way to enable the talkback feature, but it's an easy way. To disable the talkback, make sure there's a 1N914 type diode in the D-78 position. If that doesn't work, trace the D-78 circuit to make sure nobody performed the mod by cutting a trace on the solder side of the board. To locate D-78, remove the covers. Orient the radio with the speaker side up, and the display facing you. In the upper right quadrant, you'll see IC-14 (the audio IC) mounted to the chassis. You'll also see T-1 to the left of IC-14. D-78 is toward the front of the radio a bit from T-1. I hope this helps and good luck. Remark from Eric erice@fvmail.com WEB: http://www.boomerscb.com The removal of D-78 will indeed provide a talkback, but it will be very scratchy and distorted. Try it this way instead: 1. Cut D-78. Wire a SPST switch in series with D-78 to make it switchable. 2. Replace D-115 with an .0047mf disc cap. You will now have a clear and natural sounding talkback guaranteed to make you smile! Eric at Boomers CB Sales Utility Tricks Courtesy of Michael Smoot msmoot@tristate.pgh.net I've just read thru the FAQ's area of your web page, and their is a few things that need to be added to the RCI 2950 cures. First of all: Older 2950s with battery backup will discharge the battery if the power source is removed and the radio is left in the "ON" position. This causes corruption in the memory circuits and in the microprocessor. This can cause the failure to turn on. Lights on and nothing else. Also found other faults: The 8 volt regulator that is on the left side of the radio (speaker side up, front closest to you) the regulator favors the front of the radio, anyhow, I have seen 3 or 4 radios that had the turn on with no receive or transmit. The cause: cold solder joint on the regulator, this could be caused by the stressing of the chassis during mobile installation or dropping, bumping of the radio. The cure: remove old solder from regulator and re-solder. Don't attempt to remove the regulator from the chassis, it's attached there for a reason, heatsink. One other fault: Warbling on SSB. Be sure to use the proper power cord that came with the radio, don't use the radio shack substitution. The wire gauge is smaller and thus won't be able to pass enough current thru the wires. This causes the warbling effect on SSB. Also try turning down the mic gain on SSB when running a power mic. Oooopppsss! forgot one other thing! Wire the radio backwards (reverse polarity) usually causes the power regulator for AM to short out. This will give the radio a 40 Watt carrier with no modulation. This is not to be done intentionally, just letting you know what the radio is able to do without power control. Hope this info helps out. If you have any questions that I might be able to help out with, post them in the RCI Mailing List. I would like to be a part of the "GROUP." 2950 Tune up/Mod Again from a fantastic visitor: bobg@bright.net To increase heat dissipation and durability and a decrease of transmit voltage drop change Q-51 to an ECG37 or equiv. To prevent overheating and increase audio Quality & low pwr swing change Q53 from a 2SA473 to an ECG-153. To improve low power swing on AM locate R178 and change to a 3k ohm. The resister you just removed save for the next step. (4.7k) Locate R194 (10k ohm) replace with the 4.7k resistor from previous step. Locate R281 (4.7k ohm) replace with the 10k resistor from the previous step. For increased output on SSB and AM locate C270 and parallel with a 470pF-1kv ceramic disc capacitor. Replace all plastic insulators with mica insulators on all transistors. Use a liberal amount of heat sink compound. |
Heavy Swinger Mod
You should take care when you try to modify the wiring of microphones because of the presence of +12 volts on one pin of the mic socket. This particular feature may damage mic's.(NOTE: I'm not sure this person knows what he is talking about as I havn't found +12 volts on the 2950 pins)Maybe he is talking about the Realistic 5 pin "DIN" plugs which do have +12 volts on pin 3.
Cocoa, Florida
Radio Sales & Service
|
