| DX 2527 VR 1....AM/FM S-Meter VR 2....SSB S-Meter VR 3....SSB Squelch Range VR 4....AM/FM Squelch Range VR 7....SSB Carrier Balance VR 8....RF Meter VR11...Driver Bias VR12...SSB ALC VR13...Hi Power VR14...AMC VR15...AM Low Power VR16...SSB Low Power VC 1....10.240 VC 2....10.240 |
| DX 2517 VR 1....AM/FM S-Meter VR 2....SSB S-Meter VR 3....SSB Squelch Range VR 4....AM/FM Squelch Range VR 5....FM Deviation VR 6....SSB Carrier Balance VR 7....TX Offset VR 8....CW Beep Level VR 9....RF Meter VR10...Final Bias VR11...Final Bias VR12...Driver Bias VR13...SSB ALC VR14...AM/FM High Power VR15...AM Modulation Meter VR16...AM Modulation VR17...SSB Power VR18...AM/FM Low Power VR601..13.8 Volt Power Supply |
| DX 22B VR 1....AM/FM S-Meter VR 2....SSB S-Meter VR 3....SSB Squelch Range VR 4....AM/FM Squelch Range VR 7....SSB Carrier Balance VR 8....RF Meter VR11...Driver Bias VR12...SSB ALC VR13...High Power VR14...AMC VR15...AM Low Power VR16...SSB Low Power VR21...TX Offset VC 1....10.240 VC 2....10.240 |
| DX 11B VR 1....AM/FM S-Meter VR 2....SSB/CW S-Meter VR 3....SSB Squelch Range VR 4....AM/FM Squelch Range VR 5.....FM Deviation VR 7....SSB Carrier Balance VR 8....RF Meter VR10...Final Bias VR11...Driver Bias VR12...SSB ALC VR13...AM/FM High Power VR14...AM Modulation VR16...CW Tone Level VR20...Final Bias VR21...TX Offset VR601..13.8 Volt Power Supply VR803..AM/FM Low Power |
| DX 77HML, DX 88HL, and DX 99V VR 1....AM/FM S-Meter VR 2....SSB S-Meter VR 3....SSB Squelch Range VR 4....AM/FM Squelch Range VR 5.....FM Deviation VR 7....SSB Carrier Balance VR 8....RF Meter VR10...Final Bias VR11...Driver Bias VR12...SSB ALC VR13...AM/FM High Power VR14...AM Modulation VR16...AM/FM Low Power VR20...Final Bias VR21...TX Offset Unmarked VR in R189..AM/FM Medium Power for DX 77HML only |
| DX 33HML, DX 44V, DX 55V, DX 66V, and DX 73V VR 1....AM/FM S-Meter VR 4....AM/FM Squelch Range VR 5.....FM Deviation VR 8....RF Meter VR12...Low Power AM Modulation VR13...AM/FM High Power VR14...High Power AM Modulation VR16...AM/FM Low Power Unmarked VR in R188..AM/FM Medium Power (DX 33HML only) Unmarked VR in C139..Med Power AM modulation (DX 33HML only) |
| DX 949,DX 959 VR 1....AM S-Meter VR 2....SSB S-Meter VR 3....SSB Squelch Range VR 4....AM Squelch Range VR 6.....SSB Carrier Balance VR 7....TX Offset VR 9....RF Meter VR10...Final Bias VR12...Driver Bias VR13...SSB ALC VR14...AM High Power VR15...AM Modulation Meter VR16...AM Modulation VR17...SSB Power VR18...AM Low Power VC1....10.240 |
| DX 2517 and DX 2527 Symptom:Buzzing or motorboating sound in either the transmit or receive Problem: TR602 is oscillating Cure: Replace C602 with a .01uF cap {Cap is located in the power supply board} | RG 66,99,DX2517 Replace Q54 2SB754 60watt 7A with a higher power 2SB817 100 Watt 12A. Derating of this component will cool operation, provide better voltage stability,decrease wobble, allow voltage increase to 14.5 volts comfortably. (replace 10 volt caps in this section of the radio to a minimum of 16 volts before increasing supply voltage to this level)and provide faster swing rise time, Replace Q37 2SA473 to a 2SA1012-0 or ECG153 this will improve the clarity and volume of the modulation and it will also run a lot cooler. |
Disabling Talkback
DX 33HML | Disconnect wire located in TR30 |
DX 44V | Disconnect wire located in J15 |
DX 66V | Disconnect wire located in J15 |
DX 73V | Disconnect wire located in J15 |
DX 77HML | Disconnect wire from resistor R244 |
DX 88HL | Disconnect wire located in R189 |
DX 99V | (original type echo board) Disconnect wire located in TR35 |
DX 99V | (smt type echo board) Disconnect wire located in J15 next to R244 |
DX 11B | Disconnect wire from diode located in R244 |
DX 22B | Disconnect wire from diode located in R327 |
Talkback Mod Talkback can become distorted if these radios have been "peaked," and there is no cure because the talkback just amplifies what goes to the RF section. Try adding a 470k ohm resistor from junction of C155/R207 to the junction of C187/R235 on the solder side of the board. This will also give you clean talkback on SSB and FM. Try different values of resistance to get the amount of volume you want. The less the resistance the louder the talkback will be. |
DX 2517
- Symptom:
- Talkback squeals when mic gain is at max
- Problem:
- Excessive drive to IC-8 pin 4
- Cure:
- Replace R-221 with a 200K ohm resistor
|
Clarifier Mods
Some people have asked how to make the fine clarifier control track on transmit and receive like the coarse clarifier control. Below are the mods for our 10 Meter SSB mobile models (DX 77HML, DX 88HL and DX 99V) as well as the mod for the DX 2517.
10 Meter SSB Mobiles
| DX 2517
|
DX 2517 and DX 2527
- SYMPTOM:
- Buzzing or motorboating sound in either the transmit or receive
- PROBLEM:
- TR602 is oscillating
- SOLUTION:
- Replace C602 with a .01uF cap
- Remove C608
