TS-2000 Review and Modifications

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TS-2000 Review and Modifications

Post by Voodoo Guru »

Howdy all you TS-2000 Owners,
We know you've been waiting on some Voodoo Modification News on the TS-2000.
So here's a copy of a document that was written on just that subject.

A word of warning, the TS-2000 uses the next smaller generation of SMD devices.
These are Super Small!!! It's not an easy mod.
Almost not worth doing it.



Here are the instructions for the TS-2000 Audio Mods.
We're a little disappointed in the final result of these mods, but think we were expecting too much compared to the TS-950SDX.
Ultimately, the DSP circuits in the TS-2000 limit the Low Frequencies in the RX Audio and accentuate the highs.
As a result of this, Kenwood designed MASSIVE High Cut filters in the Audio Strips to try and level the audio out.
This resulted in tubby and muffled Audio on a stock TS-2000.
After the AF Strips were flattened, then it was discovered that the DSP unit was the culprit and there was nothing that could be done about that.
We've compiled some emails that were sent out to give a description of these mods and how they turned out.
Also included are edited pictures taken while incorporating these mods.

Copied from emails……

Well when we first got it, we HATED it!!

RX Audio-
The Audio from the headphone jack was very boomy with no highs, even with the N2GX user EQ it sounded tubby.
We then listened out of the ACC2 Jack and that audio was very shrill, completely different then the headphones.
That told us that the AF Audio path thru the Main amplifier to the headphones was limiting the high frequencies severely.

When you listened with no antenna or listened to low signals present at the antenna with the headphones, you heard a rumble in the headphones.
The SpectraPlus showed the high freq roll off was almost 10db per octave.
There was a peak of white noise at 30hz and by the time it got to2kc it was down 45db!!!!
As soon as you put a signal to it, the high frequencies came up but the rise in the low frequency was still there.
A tap was place directly on the DAC (Digital to Analog Converter) following the DSP and
it was found that the Rise in the Low frequencies was not present.
It was determined that a Carrier Sweep was going to have to be used for testing,
as the latent white noise from the AF Strip was creating erroneous readings.

TX Audio-
The TX Audio was OK but the highs still needed to be pushed pretty hard.
We surmised there was also a high cut filter on the audio input to the ADC (Analog to Digital Converter).

RX Sensitivity-
We were very disappointed in the RX Sensitivity, especially on VHF and UHF.
An S9 Signal was sent from the Signal Generator to measure this, the VHF was down by 4 S units and the UHF by 8.
HF had a white noise hiss behind it even on fairly strong signals.
There was also a hint of distortion on all received audio, assume it is RX IMD.

The Fan was hideously loud!

The Display was putrid!!! Gave us a Headache looking at it.

After the Extensive Mods that have been done to the rig, these are the impressions we have now:

Changed the lamps out to Blue 15,000mcd LED's and its beautiful now.

Changed the fan out to a Noctua NF-R8, and added a 100 ohm resister from the negative lead to ground.
This quieted the fan TREMENDOUSLY!!
The fan now stays on all the time at a very low speed.
If the chassis gets hot enough then the temp sensors will engage and the fan will revert to normal speed,
but at considerable less noise as the Noctua is a very quite fan.

RX Sensitivity-
Researched this and found out that the pre 2006 models (70 million and down) had the wrong Preamp bias resistor installed.
This was not letting the Preamp have the gain it should.
There is a mod to strap a resistor across the wrong one and it brings the bias up to correct value.
Kenwood fixed this on the 2006 models and later (80 million and up)
Our TS-2000 is a 2006 - 80 million version and took it apart and verified that the resistance values were correct.

Then checked the alignment and the IF tuning slugs were WAY out.
Peaked these slugs and the receiver sensitivity came up considerably.
Then installed the Adjustment Firmware and checked the IF Gain values...
They were WAY down!!!!!
We input the signal generator as per the service manual and set these correctly for all the bands.
Now when the S1, S9, and Full S meter Signals were sent to the rig,
It was dead on the money on every band.
The sensitivity is acceptable now.

The white noise problem was determined to be low quality switching diodes used in the bandpass filters.
We have some HP5082-2800 Low Noise Schottky diodes that we considered installing,
but Schottky diodes are notorious for IMD used in this application.
We believe there is already a problem with RX IMD and did not want to add to it.
The best Diodes to use would be the HP5082-3081 PIN diodes.
These are quite expensive and would cost over $120.00 to try and we're not in a position to accomplish that to date.

TX Audio-
Changed C648 & C649 on IC529 of the Control Board out to 330pf and 3300pf to make the roll off at 7kc instead of 3.3kc.
We also remove the Tantalum caps C646 & 647 and changed them to 10uf Ceramic chip caps.
This improved the Resonance and Clarity of the TX Audio.

RX Audio-
1 - Found that Kenwood had installed a RC Low Pass Filter at the Headphone Jack that rolls off the high frequencies at 663Hz!!!!!
We changed out the 4ea 1uf chip caps to .1uf caps. This gave a new roll off freq of 6Kc.
BIG improvement there.

2- Found Low Pass Filters on the Control Board at IC527 and IC528 Pre-Amplifiers for the Headphone and ACC2 Jack.
These are directly after the DAC's. The Roll off frequencies were at 2.2Kc.
Changed C613, C624, C626, and C635 to 3300pf
Changed C614, C625, C627, and C636 to 330pf
This made the new roll off point at 6kc.
Also changed Tantalum Caps C615, C616, C622, C623, C628, C629, C633, & C634 to 10uf Ceramic Chip Caps.
These changes brought the High Frequencies up a great amount.
It also took the Tubby sound out.

3- Found Low Pass Filters on the RX1/TX1 Board at IC9 rolling freq off at 589Hz!!!!!
Changed C395 and C406 to .001uf which made the new rolloff at 5.8Kc.
Also changed Electrolytic Caps C397 and C405 to 100uf FC Panasonic.
All other Electrolytic's were changed to FC Panasonic but values remained unchanged which include
C396, C398, C399, C401, & C403

This Flattened out the Audio to 4kc.
But now there was a hump in the High Frequencies and the Low Frequencies were not extended.
The Audio sounded flat and 2 dimensional although very clean and crisp.

The Audio was tapped directly at the DAC coming from the DSP for comparison.
As was thought, it was the DSP delivering the Audio in this condition.
This is why Kenwood decided to use so much High Frequency attenuation in the AF strip.
They used this attenuation to roll off the highs enough to balance it with the residual Low frequencies.
This is why the stock audio sounded so Boomy and out of balance.

Well the next step was to try and get some lows in the Audio and balance it.
The Adjustment Firmware was reloaded and it was thought that the Carrier Offset could be adjusted to balance the Tone.
No Joy., they use what they call a Filter Window Adjustment, which is like an IF Shift for the Filters.
They could only be moved a minute amount before it affected the Filter Bandwidth Control Settings.
I was able to get some lows though.

It was determined that there is nothing that can be done for the DSP Audio.
The only recourse was to develop another User EQ using the N3GX software and EQ the DSP somewhat.
We were able to get the Curve Flat to 4Kc with some low end.
It’s tricky, and took many days of trial and error with the hexadecimal code.
You can download it here:

You can run the Carrier Sweep and see it flat from 30Hz to 4Kc, but when you listen to it, the lows are slightly missing.
We're just expecting too much out of it.
It definitely isn't a VMSDX!!!

Regardless of the above, the rig is now acceptable and considered a Keeper.
It works perfectly on VHF and UHF. So good in fact we worked some EME to Russia just this morning on 2 meters JT65B.
We think it sounds great for what it is.

All in all, I really don't know if the End justifies the Means.
One Mod I would definitely suggest you do is the Headphone Jack.
But be aware, once you do that, the N3GX EQ will not be flat anymore.

OK, A bit wordy but that’s what we think of the TS-2000.

Pictures follow…..














Here is a Carrier Sweep of the Audio Before and After of the Mods:
The Yellow Line is the Stock TS-2000.
The Beige line is the Modified TS-2000.


Well that's all Folks!!!
These were shown for educational purposes only and we are not to be held responsible
for any damages to you, yourself, your radio, your house, or your spouse.
Again, We feel that the mods shown here are not worth the trouble and effort.
This is due to the DSP Chips audio frequency response.
You would be better to try and find a TS-950SDX and perform the mods to it.
Take Care,
Voodoo Guru
From Deep in the IDD of the Sub-Harmonix Realm

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TX Mod in TS-2000

Post by PU2THW »

Hi Voodoo Guru, i'm Eric PU2THW from Sao Paulo, Brazil... How are you? I wanna do the mod of TX Audio in my TS-2000, because TS-950sdx and DSP-100 (to use with 850) s very hard to find here in Brazil. Do you have any record transmiting with the VooDoo modified TS-2000? And about bandwidth? I will transmit with 7kc or the DSP will cut that?
Thanks and 73.
PU2THW - Eric.

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Post by Voodoo Guru »

Howdy Eric,
These mods were for the Receiver.
Unfortunately, the Transmit Bandwidth of the TS-2000 is only about 3.5Kc. There is no known way to make this wider.
Take Care,
Voodoo Guru
From Deep in the IDD of the Sub-Harmonix Realm

Audio Head
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Joined: Tue Mar 02, 2010 11:08 pm

Post by PU2THW »

Thanks for reply Mike. To receive i'm using a MOD to pick a 12khz FI and put into a soundcard of my computer. And using the POWERSDR If Stage. This mod is awesome. Now in SSB i'm listening a flat 6khz and a bit more with some atenuation. But do this mod in TX to give around a 3.5kc i think is a lot of work to have a little improvement.
Thanks Mike, and 73 from Brazil.

PU2THW - Eric - Sao Paulo - Brazil

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Up to 7kc wide TX audio for the TS-2000.

Post by g7vkk »

Hello all,

A while ago I managed to achieve a wider (6-7kc) and cleaner SSB tx audio bandwidth on the TS-2000 by generating my own TX I.F. signal at 12khz using computer audio software. This allows the DSP to be bypassed on transmit. The method has its limitations, namely in being tied to a PC. It is probably possible to build a circuit to do this.

Interestingly, I have contacted our licensing regulator directly myself on the topic of ESSB and I have been advised that it is quite acceptable (in the spirit of 'experimentation' of the hobby) providing that no interference is caused. Testing and appropriate audio configuration is the most important factor here before going on air to ensure that no spurious emissions result; however initial very thorough tests have proven very successful. Even with a lower bandwidth of 2.7 to 3kcs, it is possible to get a much cleaner and customisable sound.

I think the key here is being considerate to other band users; but this is something I think it is very important that opponents to ESSB ought to take on board too.

If anyone is interested on finding out more about how to input your own TX I.F. signal, please see my page on this subject:




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