Project: Kenwood 9G (9000G)

[Super Noob]

Here is the latest project / rebuild / restore.

Kenwood 9G is the largest receiver that I have (in physical size)... it is huge. Found locally and was cosmetically in fine shape. Unit was supposedly sold at military exchange. 120V / 240V selection (capability) is located on the back of the unit.

80 WPC

Here is what I started with:

Here is the rebuild PDF (cap lists & transistors).
https://drive.google.com/file/d/1q6ym-DPl2syVjOTgTUDRlkveAS8Pguox/view?usp=sharing

 

[Super Noob]

Power Amp / Power Supply (X07-1650-80)
Ce1-Ce2 - Original 2.2uF 35v (LL) / Now 2.2uF 63v (WIMA MKS2SC042201KJC00)
Ce7-Ce10 – Original 100uF 10v / Now 100uF 16v (NICH UKA1C101MDD)
Ce15-Ce16 – Original 100uF 10v / Now 100uF 16v (NICH UKA1C101MDD)
Ce17-Ce18 – Original 47uF 63v / Now 47uF 63v (NICH UPW1J470MPD)
Ce19-Ce22 – Original 47uF 10v / Now 47uF 16v (NICH UKA1C470MDD)
Ce30 – Original 47uF 16v (BP) / Now 47uF 25v (NICH – MUSE)
Ce31 – Original 47uF 16v (LL) / Now 47uF 25v (NICH UKL1E470KED)
Ce33 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Ce34 - Original 2200uF 10v / Now 2200uF 16v (NICH UPW1C222MHD)
Ce35-Ce36 - Original 10,000uF 56v / Now 12,000uF 80v (CHEMI-CON ESMH800VNN123MA63T)
Ce41-Ce42 – Original 100uF 16v / Now 100uF 35v (NICH UPW1V101MPD)
Ce43– Original 100uF 25v / Now 100uF 35v (NICH UPW1V101MPD)
Ce44 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cg45 - Original 220uF 25v / Now 220uF 35v (NICH UKE1V221MPD6)
Ce46– Original 100uF 25v / Now 100uF 35v (NICH UPW1V101MPD)
Ce47 – Original 100uF 16v / Now 100uF 35v (NICH UPW1V101MPD)
VRe1-VRe2 – 100 Ohm Bias Trimmer (Found Trimmers were 200 ohm) / Replaced with 100 Ohm (Dialed Right In)

This is a large dual purpose board at the back of the unit. Bottom center rib / galvanized cross member was removed to facilitate component replacement. The board had some suspect solder joints - cleaned and re-flowed.

 

[Super Noob]

Here are some more pics of the main filters / bypass caps / VRs / relay:

 

[Super Noob]

To get good access to the front boards - I removed the main heat-sinks and main channel cross member.
*this rebuild is not impossible = but it is likely not for everyone. (some disassembly required)

 

[Super Noob]

CONTROL (X11-1510-80)
Ci1-Ci2 - Original 220uF 6.3v / Now 220uF 16v (NICH UKA1C221MED)
Ci3-Ci4 - Original 100uF 10v / Now 100uF 25v (NICH UKL1E101MPDANA)
Ci5-Ci6 – Original 10uF 25v / Now 10uF 35v (NICH UKL1V100MDDANA)
Ci17-Ci18 - Original 2.2uF 35v / Now 2.2uF 63v (WIMA MKS2SC042201KJC00)
Ci19-Ci20 - Original 100uF 10v / Now 100uF 25v (NICH UKL1E101MPDANA)
Ci21-Ci22 – Original 10uF 25v / Now 10uF 35v (NICH UKL1V100MDDANA)
Ci21-Ci22 - Original 100uF 10v / Now 100uF 25v (NICH UKL1E101MPDANA)
Ci27-Ci28 - Original 2.2uF 35v / Now 2.2uF 63v (WIMA MKS2SC042201KJC00)
Ci29-Ci30 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Ci31-Ci32 - Original 100uF 10v / Now 100uF 25v (NICH UKL1E101MPDANA)
Ci33-Ci34 – Original 10uF 25v / Now 10uF 35v (NICH UKL1V100MDDANA)
Ci35-Ci36 - Original 2.2uF 35v / Now 2.2uF 63v (WIMA MKS2SC042201KJC00)
Ci43-Ci44 – Original 100uF 25v / Now 100uF 35v (NICH UKL1V101MPDANA)

Dirty:

Cleaned Up Before:

After:

Took time to deOxit all the controls and flush with Faderlube.

 

[Super Noob]

DOLBY (X14-1110-80)
Cv1-Cv2 - Original 1uF 25v (Tant - LL) / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cv9-Cv12 - Original 10uF 25v / Now 10uF 35v (NICH UKT1V100MDD)
Cv15-Cv16 - Original 10uF 25v / Now 10uF 35v (NICH UKT1V100MDD)
Cv23-Cv24 - Original 10uF 25v / Now 10uF 35v (NICH UKT1V100MDD)
Cv27-Cv28 - Original 10uF 25v / Now 10uF 35v (NICH UKT1V100MDD)
Cv29-Cv30 - Original 220uF 16v / Now 220uF 25v (NICH UKA1E221MFD)
Cv33-Cv34 - Original 1uF 25v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cv35-Cv36 - Original 10uF 25v / Now 10uF 35v (NICH UKT1V100MDD)
Cv37 - Original 100uF 25v / Now 100uF 35v (NICH UKA1V101MED)

Before:

 

[Super Noob]

METER / SPEAKER SELECTOR (X13-2550-80 (A4/C4)
Ch1 - Original 47uF 10v / Now 47uF 25v (NICH UKL1E470KED)
Ch2 - Original 47uF 10v / Now 47uF 25v (NICH UKL1E470KED)
Ch5 - Original 2.2uF 35v (LL) / Now 2.2uF 63v (WIMA MKS2SC042201KJC00)
Ch6 - Original 2.2uF 35v (LL) / Now 2.2uF 63v (WIMA MKS2SC042201KJC00)

After:

Cleaned the switches with the D5 and flushed with F5.

 

[Super Noob]

Tuner, Pre Amp, Selector (X05-1570-80)
Cg21- Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg23 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cg25 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cg30- Original 10uF 16v / Now Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg31 - Original 33uF 16v / Now 33uF 25v (NICH UKA1E330MDD1TD)
Cg32 - Original 47uF 16v / Now 47uF 25v (NICH UKA1E470MDD)
Cg33 - Original 100uF 10v / Now 100uF 25v (PANA EEU-FM1E101)
Cg45 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg49 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg51 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg52 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00
Cg58 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg61 - Original 47uF 16v / Now 47uF 35v (NICH UKA1V470MDD)
Cg64 - Original .22uF 50v / Now .22uF 63v (WIMA MKS2C032201B00JA)
Cg65 - Original .47uF 50v / Now .47uF 100v (WIMA MKS2D034701E00JI)
Cg66 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cg71 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg72 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg75 - Original .47uF 50v (LL) / Now .47uF 100v (WIMA MKS2D034701E00JI)
Cg76 - Original .47uF 50v (LL) / Now .47uF 100v (WIMA MKS2D034701E00JI)
Cg77 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg78 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg79 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg80 - Original 10uF 16v / Now 10uF 25v (NICH UKT1E100MDD1TA)
Cg85 - Original 220uF 25v / Now 220uF 35v (PANA EEU-FM1V221L)
C93 - Original 3.3uF 10v (LL) Tant / Now 3.3uF 63v (WIMA MKS2C043301KKSSD)
C94 - Original 3.3uF 10v (LL) Tant / Now 3.3uF 63v (WIMA MKS2C043301KKSSD)
Cg95 - Original 47uF 10v / Now 47uF 16v (NICH UKA1C470MDD1TD)
Cg96 - Original 47uF 10v / Now 47uF 16v (NICH UKA1C470MDD1TD)
Cg105 - Original 4.7uF 25v (LL) / Now 4.7uF 35v (WIMA MKS2C044701M00JO)
Cg106 - Original 4.7uF 25v (LL) / Now 4.7uF 35v (WIMA MKS2C044701M00JO)
Cg107 - Original 100uF 25v / Now 100uF 35v (NICH UKA1V101MED)
Cg108 - Original 100uF 25v / Now 100uF 35v (NICH UKA1V101MED)
Cg111 - Original 100uF 25v / Now 100uF 35v (NICH UKA1V101MED)
Cg112 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)
Cg117 - Original .47uF 50v (LL) / Now .47uF 100v (WIMA MKS2D034701E00JI)
Cg119 - Original 33uF 16v / Now 33uF 25v (NICH UKA1E330MDD1TD)
Cg120 - Original 1uF 50v / Now 1uF 63v (WIMA MKS2C041001FJC00)

Before:

This tuner alignment remained spot on and the FM pulls in Radio Tokoyo without any antenna.

 

[Super Noob]

Output Transistors: Cleaned / Re-Greased

 

[Super Noob]

Up Next Are New Lights:

Obviously if you like more of the original green illumination of the dial, white LEDs are not for you. I like the blue (similar to white LEDs in my 2325 / 2275 / 2270). I like white LED and blue illumination. Different strokes for different folks.

 

[Super Noob]

Will take a "timeout" to review the timer. This unit has already had the "coupler upgrade". However, I was hesitant to apply the strong force needed to get it going counterclockwise (initially). After reviewing the mechanics of the time switch - I was more comfortable getting it going in CCW.

Here are some pictures that might help someone:
OFF POSITION

RESET POSITION:

Here is the coupler used (large wire junction connector)

Timer Assembled:

So to get the reset position (that I like to leave it in), I turn forward clockwise a bit - then go counterclockwise. It gives us some momentum to bump through the off position stop over to the reset position.

 

[Super Noob]

Reassemble, dial up the bias (to spec), and tested. Offset improved from over 60mv to ~30mv on each channel. During first test session, the unit would go into oscillation (hum). Suspected a weak transistor in the amp / power supply. Went ahead and replaced them all (minus the outputs). Did the trick... I have yet to replace small transistors and didn't like the results.

VOLTAGE REGULATOR
De13 / De14 / V06B / MUR220RLG (2A UltraFast)
De17 / XZ-132 / 1N4743ATR (13V, 1 Watt Zener)
De18 / WZ-240 / 1N4749A (24V, 1 Watt Zener)
Qe30 / 2SD330 / MJE15032G
Qe31 / 2SC1775 / KSC1845
Qe32 / 2SA850 / KSA1220AYS
Qe33 / 2SA850 / KSA1220AYS

AMP
Qe1-Qe4 / 2SA921 / KSA992 (HFE Matched)
Qe5-Qe6 / 2SA872 / KSA992 (Constant Current)
Qe7-Qe8 / 2SC1775 / KSC1845 (Current Mirror)
Qe9-Qe10 / 2SC1885 / KSC2690AYS (2nd Stage)
Qe11-Qe12 / 2SA912 / KSA1220AYS (2nd Stage)
Qe13-Qe14 / 2SA733 / KSA733YTA (rework legs)
Qe15-Qe18 / 2SC945 / KSC945YTA (rework legs)
Qe19-Qe20 / 2SA733 / KSA733YTA (rework legs)
Qe21-Qe22 / 2SA1913A / KSA940TU (Driver Stage)
Qe23-Qe24 / 2SC1913 / KSC2073TU (Driver Stage)

DC PROTECTION
Qe25 / 2SC945 / KSC945YTA (rework legs)
Qe26 / 2SA733 / KSA733YTA (rework legs)
Qe27 / 2SC945 / KSC945YTA (rework legs)
Qe28 / 2SC1775 / KSC1845
Qe29 / 2SC2274 / KSC2690AYS

 

[Super Noob]

Some reassembly pics:

 

[Super Noob]

SUMMARY:
19 LEDs
33 Transistors
109 Electro Caps (81 Typical Electros / 28 LL Electros)
4 Tantalum Caps
2 VRs
1 Relay
FINAL PICTURES

Have plenty of vintage gear from the popular brands (too many to list)... but I feel that Kenwood is a bit underappreciated (maybe not in this sub-forum), which can create good opportunities for us.

Here are my three Kennys... they all sound unbelievably good to my ears.

 

[dstariha]

Extensive rebuild to say the least, an admirable job. I shy away from receivers because I live in a poor signal area but I have two KA-7002 int amps that I enjoy very much.

Have fun

 

[oldboats]

Well done, and quite the stack you have going!

 

[Ace1]

The receiver is a Military exchange, I have the same one. I purchased it in the late 70's from the exchange I think for around $300. Its been a great receiver but I am having problems with my source selector that I would like to replace and cannot find a complete board that I can swap out. Any help would be appreciated, there are 2 #'s on the board J25-1588-13 A/2 and X14-1110-80 A/2.

 

[Semanon]

Welcome to AK @Ace1

This is an old thread. You might want to start a new one so the post does not get lost. Explain the problem with as much detail as possible, and what steps you’ve taken so far to fix it. There are some great techs here and almost everything gets resolved.