Just picked up a new Ranger RCI-3900HP AM/FM/CW/SSB dual (MOSFET) final radio this weekend & have been playing around & modding it. Here are my initial impressions:
Out of the box performance is DISMAL (at best). Review can be found here: YouTube - RCI 3900HP Review It was off freq and not powered up.
The rig is similar to a Galaxy DX-77HML & uses the EPT3600 board (so most OLD Galaxy Mods will work on it.)
Here's what I have gathered thus far on the radio:
EPT360015C BOARD
PREDRIVER = 2SC2314 1.8W device
DRIVER = IRF520 MOSFET
FINALS = DUAL IRF520 MOSFETS
VR POTS:
VR1 = AM/FM S-METER
VR2 = SSB S-METER
VR3 = SSB SQUELCH
VR4 = AM/FM SQUELCH
VR5 = FM DEVIATION
VR7 = SSB CARRIER BALANCE
VR8 = RF METER
VR10 = FINAL BIAS
VR11 = DRIVER BIAS
VR12 = SSB ALC
VR13 = AM/FM POWER
VR14 = AM MODULATION AMC
VR20 = FINAL BIAS
MODULATION LIMITER = TR32 (2SC945), which will disable AMC PLUS ALC, so you will lose L/M/H on SSB. Therefore, you should NOT remove this limiter, merely clip R249 for AMC only.
ROGER BEEP - like the 'old school' SS-3900's, the Roger Beep is ALWAYS ON. To disable, clip J9 jumper, or add a SPST switch to make it switchable.
RX RF AMPLIFIER - this radio already comes with a low noise / moderate gain device (2SC2876) in the TR17 slot. The 2SC2876 is a 3 dB noise / 22 dB gain device.) There is only slight benefit to upgrading to a 2SC2999 (2.2 DB noise / 28 dB gain) device. I DID change it to a 2999, and (after realignment) only noticed marginal improvement. Selectivity, which isn't all that good on this radio to begin with, may even SUFFER from the additional gain. Too soon to tell..... will keep you posted.
STOCK MIC - Another benefit of this radio is the fact that it comes with a Ranger SRA-158-4H stock mic, which is highly rated here: Texas Ranger SRA-158 Microphone Review
CHANNELS: In the box with the mic comes a programming KEY which must be installed (just like the RCI-2950DX Blue Dot). Locate the programming module and plug into the socket next to IC2. Locate the adjacent JP3 and temporarily short the pins of JP3 while powering the radio on. This will cause the programming module to write the data to the CPU chip. After installing the module, you get 6 banks of 40 channels, for a freq coverage of 26.615 - 28.305 MHz.
10KC Switch: non existant in this radio.
Clarifier: Coarse clarifer is UNLOCKED, and tracks transmit. Fine clarifer is LOCKED, and works on RX only. Once you align the radio on AM, USB and LSB for the center detente of the coarse, as long as you don't have any severe temp swings, you should be fine. IS THERE A MOD FOR THE FINE CLARIFIER ON THIS RADIO YET???
Modulation / Voltage Power Amplifier: Rig comes with the 2SB827 (60W) replacement for the 2SB754 as TR51. First thing I did was change this to a 100W device: 2SB817
AM AF Amplifier: Rig comes with the 2SA1869 transistor in the TR50 slot. I changed mine to a 2SA1012 (NTE153 is also acceptable).
AM Product Detector Diodes: D23 & D24 are 1N60 silicon germainium diodes. I changed mine to Schottky 1N5711, but you may use NTE583 or equivalents.
Noise Blanker Diodes: For this radio, the NB diodes are D1 & D2, just like the EPT6900 chassis. They come from factory as germainium. I changed mine to 1N5711, but you may use NTE583 or equivalent.
Super Ears: I didn't perform this mod on the radio because I'll be running it mobile, but you may lift the BANDED END of diode D7, and install a 1.5K resistor to the vacant board slot where u lifted the diode. This will give you an EXTREME gain in you receiver with little background noise (especially on AM), but makes the rig EXTREMELY VUNERABLE TO RF OVERLOAD / DAMAGE. In fact, if you DO perform this mod, along with the gain obtained from the 2SC2999, you will have to keep the RF gain at 1/2 position (or lower). You will still be vunerable. Better left alone, or with a switchable mod, or for base station use only.
NPC-RC: There are two ways of doing this: First one is with R238. Lift the right leg of R238 (as you are looking at the radio, component side up and front of radio toward you) and install a 1N4001 (or equivalent) switching diode in series with the lifted resistor. This will allow you to lower the dead key and still have full swing capability of the radio on AM, to the limits of the AMC. If you removed TR32, even in LOW power mode, on AM radio will modulate to the maximum limits of the radio. I KEPT TR32 INTACT.
Method 2 of NPC-RC (formerly known as the M.C. Turner Super-Swing Mod) is installing a 1N914 diode in series with a 50 ohm resistor and paralleling this across the center terminal of the newly installed 2SB817 to the other side of the audio circuit. I didn't try this on THIS particular radio, but I have used it in the past with 2SC1969 rigs. I'm not quite sure the MOSFETS could take the abuse, so I didn't try this. DON'T DO BOTH mods, as it won't work.
Performance after modification:
AM/FM DEADKEY L/M/H: 3 / 7 / 13 watts
AM RMS SWING WATTS L/M/H: 6 / 12 / 13 watts
AM PEAK SWING WATTS at 100% Modulation L/M/H: 35 / 50 / 50 watts
SSB PEP WATTS (two tone test) L/M/H: with TR32 intact and ALC adjusted for max: 6 / 15 / 40 watts SSB PEP
SSB PEP WATTS (two tone test) L/M/H: with TR32 removed (completely bypasses ALC <and AMC> circuitry: 50+ watts SSB PEP (but flattopping occurs). So, because I like to operate SSB, and I am using a Road Devil noise cancelling power mike, I reinstalled TR32.
Frequency Drift and Stability: no worse than my DX-949, or other Galaxy chassis radios I've used. Once it warms up, it's pretty good; only needs occasional adjustment after heavy use.
PROS / CONS (Likes & Dislikes):
LIKES:
- Looks, ergonomics, display are flawless. Easier to operate (especially MOBILE) than DX-949, 99V, 959, 2950's, etc.
- Built in Connex echo board with switchable talk-back feature make set up and use easy.
- L/M/H Power settings make hook up to any high or low drive amp a breeze. I have mine set up for use in the M power position on AM barefoot, and H pwr for SSB use. I use it in the L position for my low drive TX-250 (2X1446) amp. I set it up in the H position to drive my Super Cobra 677HD (4 X 2SC2879) amp for high drive.
- The fact that it has CW, (morse code) makes it a 'true' ham rig IMHO, lol
I actually used to use my old SS3900GHP on cw with a keyer. Worked every bit as good as my 2950, albeit it's a 'channelized' radio
- SWR feature doesn't require calibration (like Cobra rigs)
- MOSFET Power: these dual finals are capable of 50+ watts all day long. Because I want mine to 'last' it is tuned down somewhat.
- RX Sensitivity: either WITH or WITHOUT the 2SC2999, this thing has ears!
- AM Transmitted Audio: At least as good as a General Lee or a General Washington (they share the same board after all), this thing is an AM AUDIO MONSTER when properly set up.
DISLIKES:
- No 10KC switch. Is there a MOD for this?
- Lotsa feedback with the Talkback, especially when using a power mic, unless you turn down the gain.
- Damn PERMANENT Roger Beep, unless you cut J9. They should've made it switchable like the DX77HML
- SSB needed alignment right out of the box. This I would've expected from Galaxy, but RANGER??? I guess there's a shortage of frequency counters in Malaysia hihi.
- Selectivity is NOT as good as a Cobra 148GTL or Texas Ranger TR-296, and slightly worse than a DX-949 or DX-959 chassis. I was mobile on channel 19 AM, and could hear splatter from local KW mobiles on Superbowl AM channel 6. (another reason NOT to perform the 'SuperEars' mod on this radio chassis)
OVERALL:
I think it's IDEAL for the mobile due to the fact that it LOOKS like a standard CB it may be less likely to get stolen. Also, because I live in the North East, I'm always afraid that LCD displays will FREEZE in the winter. (This thing has LED). It absolutely BOOMS on the AM side, and is quite acceptable for SSB once aligned & up to temperature. Variable (switchable) output power levels make it suitable for a variety of applications, high drive, low drive or barefoot. It's easy to use, and quite stylish (if you like 'Old School' looking radios.) The built-in echo board with talk back give the rig a 'fun factor' lacking in 2950's, 2510/2600/Lincoln's. The circuit design does NOT stress the dual MOSFET finals to their limits, and properly adjusted, should provide trouble-free use for some time to come.
Anybody know how to further increase the freq coverage BEYOND the 28.305 limitation of the existing key chip (like the old 3900's were capable of)??? Also, anybody know how to add a 10KC switch to this rig??? Lastly, unlockiing the FINE clarifier adjustment???
Thanks
Out of the box performance is DISMAL (at best). Review can be found here: YouTube - RCI 3900HP Review It was off freq and not powered up.
The rig is similar to a Galaxy DX-77HML & uses the EPT3600 board (so most OLD Galaxy Mods will work on it.)
Here's what I have gathered thus far on the radio:
EPT360015C BOARD
PREDRIVER = 2SC2314 1.8W device
DRIVER = IRF520 MOSFET
FINALS = DUAL IRF520 MOSFETS
VR POTS:
VR1 = AM/FM S-METER
VR2 = SSB S-METER
VR3 = SSB SQUELCH
VR4 = AM/FM SQUELCH
VR5 = FM DEVIATION
VR7 = SSB CARRIER BALANCE
VR8 = RF METER
VR10 = FINAL BIAS
VR11 = DRIVER BIAS
VR12 = SSB ALC
VR13 = AM/FM POWER
VR14 = AM MODULATION AMC
VR20 = FINAL BIAS
MODULATION LIMITER = TR32 (2SC945), which will disable AMC PLUS ALC, so you will lose L/M/H on SSB. Therefore, you should NOT remove this limiter, merely clip R249 for AMC only.
ROGER BEEP - like the 'old school' SS-3900's, the Roger Beep is ALWAYS ON. To disable, clip J9 jumper, or add a SPST switch to make it switchable.
RX RF AMPLIFIER - this radio already comes with a low noise / moderate gain device (2SC2876) in the TR17 slot. The 2SC2876 is a 3 dB noise / 22 dB gain device.) There is only slight benefit to upgrading to a 2SC2999 (2.2 DB noise / 28 dB gain) device. I DID change it to a 2999, and (after realignment) only noticed marginal improvement. Selectivity, which isn't all that good on this radio to begin with, may even SUFFER from the additional gain. Too soon to tell..... will keep you posted.
STOCK MIC - Another benefit of this radio is the fact that it comes with a Ranger SRA-158-4H stock mic, which is highly rated here: Texas Ranger SRA-158 Microphone Review
CHANNELS: In the box with the mic comes a programming KEY which must be installed (just like the RCI-2950DX Blue Dot). Locate the programming module and plug into the socket next to IC2. Locate the adjacent JP3 and temporarily short the pins of JP3 while powering the radio on. This will cause the programming module to write the data to the CPU chip. After installing the module, you get 6 banks of 40 channels, for a freq coverage of 26.615 - 28.305 MHz.
10KC Switch: non existant in this radio.
Clarifier: Coarse clarifer is UNLOCKED, and tracks transmit. Fine clarifer is LOCKED, and works on RX only. Once you align the radio on AM, USB and LSB for the center detente of the coarse, as long as you don't have any severe temp swings, you should be fine. IS THERE A MOD FOR THE FINE CLARIFIER ON THIS RADIO YET???
Modulation / Voltage Power Amplifier: Rig comes with the 2SB827 (60W) replacement for the 2SB754 as TR51. First thing I did was change this to a 100W device: 2SB817
AM AF Amplifier: Rig comes with the 2SA1869 transistor in the TR50 slot. I changed mine to a 2SA1012 (NTE153 is also acceptable).
AM Product Detector Diodes: D23 & D24 are 1N60 silicon germainium diodes. I changed mine to Schottky 1N5711, but you may use NTE583 or equivalents.
Noise Blanker Diodes: For this radio, the NB diodes are D1 & D2, just like the EPT6900 chassis. They come from factory as germainium. I changed mine to 1N5711, but you may use NTE583 or equivalent.
Super Ears: I didn't perform this mod on the radio because I'll be running it mobile, but you may lift the BANDED END of diode D7, and install a 1.5K resistor to the vacant board slot where u lifted the diode. This will give you an EXTREME gain in you receiver with little background noise (especially on AM), but makes the rig EXTREMELY VUNERABLE TO RF OVERLOAD / DAMAGE. In fact, if you DO perform this mod, along with the gain obtained from the 2SC2999, you will have to keep the RF gain at 1/2 position (or lower). You will still be vunerable. Better left alone, or with a switchable mod, or for base station use only.
NPC-RC: There are two ways of doing this: First one is with R238. Lift the right leg of R238 (as you are looking at the radio, component side up and front of radio toward you) and install a 1N4001 (or equivalent) switching diode in series with the lifted resistor. This will allow you to lower the dead key and still have full swing capability of the radio on AM, to the limits of the AMC. If you removed TR32, even in LOW power mode, on AM radio will modulate to the maximum limits of the radio. I KEPT TR32 INTACT.
Method 2 of NPC-RC (formerly known as the M.C. Turner Super-Swing Mod) is installing a 1N914 diode in series with a 50 ohm resistor and paralleling this across the center terminal of the newly installed 2SB817 to the other side of the audio circuit. I didn't try this on THIS particular radio, but I have used it in the past with 2SC1969 rigs. I'm not quite sure the MOSFETS could take the abuse, so I didn't try this. DON'T DO BOTH mods, as it won't work.
Performance after modification:
AM/FM DEADKEY L/M/H: 3 / 7 / 13 watts
AM RMS SWING WATTS L/M/H: 6 / 12 / 13 watts
AM PEAK SWING WATTS at 100% Modulation L/M/H: 35 / 50 / 50 watts
SSB PEP WATTS (two tone test) L/M/H: with TR32 intact and ALC adjusted for max: 6 / 15 / 40 watts SSB PEP
SSB PEP WATTS (two tone test) L/M/H: with TR32 removed (completely bypasses ALC <and AMC> circuitry: 50+ watts SSB PEP (but flattopping occurs). So, because I like to operate SSB, and I am using a Road Devil noise cancelling power mike, I reinstalled TR32.
Frequency Drift and Stability: no worse than my DX-949, or other Galaxy chassis radios I've used. Once it warms up, it's pretty good; only needs occasional adjustment after heavy use.
PROS / CONS (Likes & Dislikes):
LIKES:
- Looks, ergonomics, display are flawless. Easier to operate (especially MOBILE) than DX-949, 99V, 959, 2950's, etc.
- Built in Connex echo board with switchable talk-back feature make set up and use easy.
- L/M/H Power settings make hook up to any high or low drive amp a breeze. I have mine set up for use in the M power position on AM barefoot, and H pwr for SSB use. I use it in the L position for my low drive TX-250 (2X1446) amp. I set it up in the H position to drive my Super Cobra 677HD (4 X 2SC2879) amp for high drive.
- The fact that it has CW, (morse code) makes it a 'true' ham rig IMHO, lol
I actually used to use my old SS3900GHP on cw with a keyer. Worked every bit as good as my 2950, albeit it's a 'channelized' radio- SWR feature doesn't require calibration (like Cobra rigs)
- MOSFET Power: these dual finals are capable of 50+ watts all day long. Because I want mine to 'last' it is tuned down somewhat.
- RX Sensitivity: either WITH or WITHOUT the 2SC2999, this thing has ears!
- AM Transmitted Audio: At least as good as a General Lee or a General Washington (they share the same board after all), this thing is an AM AUDIO MONSTER when properly set up.
DISLIKES:
- No 10KC switch. Is there a MOD for this?
- Lotsa feedback with the Talkback, especially when using a power mic, unless you turn down the gain.
- Damn PERMANENT Roger Beep, unless you cut J9. They should've made it switchable like the DX77HML
- SSB needed alignment right out of the box. This I would've expected from Galaxy, but RANGER??? I guess there's a shortage of frequency counters in Malaysia hihi.
- Selectivity is NOT as good as a Cobra 148GTL or Texas Ranger TR-296, and slightly worse than a DX-949 or DX-959 chassis. I was mobile on channel 19 AM, and could hear splatter from local KW mobiles on Superbowl AM channel 6. (another reason NOT to perform the 'SuperEars' mod on this radio chassis)
OVERALL:
I think it's IDEAL for the mobile due to the fact that it LOOKS like a standard CB it may be less likely to get stolen. Also, because I live in the North East, I'm always afraid that LCD displays will FREEZE in the winter. (This thing has LED). It absolutely BOOMS on the AM side, and is quite acceptable for SSB once aligned & up to temperature. Variable (switchable) output power levels make it suitable for a variety of applications, high drive, low drive or barefoot. It's easy to use, and quite stylish (if you like 'Old School' looking radios.) The built-in echo board with talk back give the rig a 'fun factor' lacking in 2950's, 2510/2600/Lincoln's. The circuit design does NOT stress the dual MOSFET finals to their limits, and properly adjusted, should provide trouble-free use for some time to come.
Anybody know how to further increase the freq coverage BEYOND the 28.305 limitation of the existing key chip (like the old 3900's were capable of)??? Also, anybody know how to add a 10KC switch to this rig??? Lastly, unlockiing the FINE clarifier adjustment???
Thanks
