950s
First, to be clear, there are three TS-950 rigs:
- TS-950S
- TS-950SD
- TS-950SDX
The TS-950S and TS-950SD are really identical, except for the following things:
- TS-950SD comes from the factory with YK-88C-1, YG-455C-1, YG-455CN-1 and YG-455S-1 crystal filters pre-installed
- TS-950SD comes with the SO-2 TXCO pre-installed
- TS-950SD comes with the DSP-10 unit
- TS-950SD has the word 'DIGITAL' on the front of it
You can turn a TS-950S into a TS-950SD by adding the extra filters, TXCO and DSP-10 unit yourself. Otherwise, they're the same rig. Note that this means a TS-950SD still has the analog modulation circuitry inside it for SSB and AM modes, but it's disabled when the DSP-10 unit is connected.
The thing that makes the TS-950SDX special is that its DSP unit can be configured for extra wide mode, where both the low cut and high cut DSP filter settings can be set to 'off.' This is done via the SDX's menu system. The DSP unit that comes with the TS-950SDX is _not_ the same as the DSP-10. It's a newer and improved design.
The TS-950S/TS-950SD does not have a menu system. To set the low and high cut frequencies on the DSP unit, you instead have to set some manual rotary switches that are accessible through an opening in the bulkhead on the bottom of the radio. Unlike the DSP unit in the TS-950SDX, the DSP-10 does not have any documented "off" selections for its low and high cut settings (for SSB, the widest range is from 110Hz to 3100Hz and for AM the widest range is from 75Hz to 2900Hz). The switches appear to have more than just the 4 positions documented in the user's manual, but it's not clear what would happen if you tried to undocumented settings. I don't know of anyone that's tried it.
I think the TS-950S and SD do have the ability to bypass the crystal (analog) filters during transmit. However, that alone isn't enough to give you ESSB. If you have a TS-950S and you disable the crystal filters, you'll get wider frequency response, but you'll also end up transmitting in double sideband mode. This is because Kenwood's traditional analog design uses the crystal filters to suppress the alternate sideband when operating in SSB mode. If you use the DSP unit for SSB modulation, the alternate sideband suppression is done in using digital filtering in the DSP unit instead. This is what makes the TS-950SDX special: its DSP unit can be configured for wider than normal bandwidth without sacrificing alternate sideband suppression. You still need to bypass the crystal filters, but the DSP unit makes it possible to do that without ending up operating in DSB mode.
Now, I think it should be possible to achieve wider bandwidth on _AM_ using the TS-950S, or a TS-950SD with the DSP-10 unit unplugged. On AM mode, it's okay to bypass the crystal filters since you want both sidebands. Without the DSP unit, I think the TS-950S and SD will use Kenwood's typical analog AM modulation scheme, which is to unbalance the AN612 balanced modulator to produce an AM signal instead of SSB. In theory, this means that you should be able to:
- Do a few hardware mods on the rig to reduce the low-end rolloff by changing some of the coupling caps and/or emitter shunt caps in the mic pre-amp circuits
- Bypass the crystal filters during transmit to improve the high-end response
I've done something similar with the TS-850 and it works very well. But again, this is for AM, not SSB.
So, to summarize:
- TS-950SDX can yield 6Khz ESSB (and AM) bandwidth with the DSP
- TS-950SD will do 3.1Khz max with the DSP
- TS-950S is limited to normal bandwidth on SSB, could potentially do HiFi AM
-Bill, N1GPT
- TS-950S
- TS-950SD
- TS-950SDX
The TS-950S and TS-950SD are really identical, except for the following things:
- TS-950SD comes from the factory with YK-88C-1, YG-455C-1, YG-455CN-1 and YG-455S-1 crystal filters pre-installed
- TS-950SD comes with the SO-2 TXCO pre-installed
- TS-950SD comes with the DSP-10 unit
- TS-950SD has the word 'DIGITAL' on the front of it
You can turn a TS-950S into a TS-950SD by adding the extra filters, TXCO and DSP-10 unit yourself. Otherwise, they're the same rig. Note that this means a TS-950SD still has the analog modulation circuitry inside it for SSB and AM modes, but it's disabled when the DSP-10 unit is connected.
The thing that makes the TS-950SDX special is that its DSP unit can be configured for extra wide mode, where both the low cut and high cut DSP filter settings can be set to 'off.' This is done via the SDX's menu system. The DSP unit that comes with the TS-950SDX is _not_ the same as the DSP-10. It's a newer and improved design.
The TS-950S/TS-950SD does not have a menu system. To set the low and high cut frequencies on the DSP unit, you instead have to set some manual rotary switches that are accessible through an opening in the bulkhead on the bottom of the radio. Unlike the DSP unit in the TS-950SDX, the DSP-10 does not have any documented "off" selections for its low and high cut settings (for SSB, the widest range is from 110Hz to 3100Hz and for AM the widest range is from 75Hz to 2900Hz). The switches appear to have more than just the 4 positions documented in the user's manual, but it's not clear what would happen if you tried to undocumented settings. I don't know of anyone that's tried it.
I think the TS-950S and SD do have the ability to bypass the crystal (analog) filters during transmit. However, that alone isn't enough to give you ESSB. If you have a TS-950S and you disable the crystal filters, you'll get wider frequency response, but you'll also end up transmitting in double sideband mode. This is because Kenwood's traditional analog design uses the crystal filters to suppress the alternate sideband when operating in SSB mode. If you use the DSP unit for SSB modulation, the alternate sideband suppression is done in using digital filtering in the DSP unit instead. This is what makes the TS-950SDX special: its DSP unit can be configured for wider than normal bandwidth without sacrificing alternate sideband suppression. You still need to bypass the crystal filters, but the DSP unit makes it possible to do that without ending up operating in DSB mode.
Now, I think it should be possible to achieve wider bandwidth on _AM_ using the TS-950S, or a TS-950SD with the DSP-10 unit unplugged. On AM mode, it's okay to bypass the crystal filters since you want both sidebands. Without the DSP unit, I think the TS-950S and SD will use Kenwood's typical analog AM modulation scheme, which is to unbalance the AN612 balanced modulator to produce an AM signal instead of SSB. In theory, this means that you should be able to:
- Do a few hardware mods on the rig to reduce the low-end rolloff by changing some of the coupling caps and/or emitter shunt caps in the mic pre-amp circuits
- Bypass the crystal filters during transmit to improve the high-end response
I've done something similar with the TS-850 and it works very well. But again, this is for AM, not SSB.
So, to summarize:
- TS-950SDX can yield 6Khz ESSB (and AM) bandwidth with the DSP
- TS-950SD will do 3.1Khz max with the DSP
- TS-950S is limited to normal bandwidth on SSB, could potentially do HiFi AM
-Bill, N1GPT
-
Voodoo Guru
- VooDoo Site Admin
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Howdy,
We will have to agree once again with Bill Paul as he is spot on in all that he posted.
We will add that another MAJOR difference between the DSP-10 and the SDX DSP is that the DSP-10 works ONLY during Transmit. It does not do anything for the RX except enable the Slope Tuning control. In other words, the TS-950SD only uses the Analog Crystal Filters for opposite sideband suppression even if the DSP-10 is connected.
So, about the maximum bandwidth you can listen in SSB Receive is about 3Kc. We are not really sure how far the Carrier Offset can be adjusted on the SD as it is a manual adjustment and not MENU driven like the SDX. Our guess is about 3Kc and then anything over that will be double sideband.
Take Care,
We will have to agree once again with Bill Paul as he is spot on in all that he posted.
We will add that another MAJOR difference between the DSP-10 and the SDX DSP is that the DSP-10 works ONLY during Transmit. It does not do anything for the RX except enable the Slope Tuning control. In other words, the TS-950SD only uses the Analog Crystal Filters for opposite sideband suppression even if the DSP-10 is connected.
So, about the maximum bandwidth you can listen in SSB Receive is about 3Kc. We are not really sure how far the Carrier Offset can be adjusted on the SD as it is a manual adjustment and not MENU driven like the SDX. Our guess is about 3Kc and then anything over that will be double sideband.
Take Care,
Voodoo Guru
From Deep in the IDD of the Sub-Harmonix Realm
From Deep in the IDD of the Sub-Harmonix Realm
Thanks guys I do have the 950sd. I am running a behringer 802 in to the back of the radio. I do get some great comments on it just woundered if it could get better. I am saving my money for a flex 3000. I am running the 950 with LP pan and nap3 tried power sdr and my computor did not like it. I am running LP pan in to my sound card and back out in to a set of JBL speakers. The recieve is where I want it but believe the transmite could be better. I also own a 940 and a ts 2000 both are great radios. May have to rig the ts 2000 up just do not want to have to build the circut to run LP pan but may have to.
Thanks KF5IPV
Thanks KF5IPV
-
Voodoo Guru
- VooDoo Site Admin
- Posts: 722
- Joined: Wed Feb 23, 2005 8:47 am
- Location: Down there on the right...
If the TS-950SD is anything like the TS-950SDX, then just using the ACC2 port on the back of the radio for your TX audio may not actually yield any better results than using the front panel mic jack. The ACC2 port is designed for data use (e.g. packet radio). At least with the SDX, there's also a phone patch input which feeds into the same pre-amp circuit as the ACC2 input. In both cases, you're talking about applications where good fidelity is not much of a concern. Consequently, Kenwood designed the rear panel audio input circuits so that they have an even worse low-end roll-off than what you get from the mic pre-amp.
Long story short, using the ACC2 port gives you less bass than using the front panel mic jack, unless you make a few modifications (i.e. changing out a few capacitors). This is a common design theme in most Kenwood HF rigs. Exactly what you have to modify varies a bit depending on the radio though. With the TS-870, it seems like there's just one cap that needs to be changed, which makes it a popular choice. With the TS-950SDX, there's about 5 of them. (The preferred method is to bypass the pre-amp circuits entirely.)
Unfortunately, I don't know offhand how similar the 950SD's ACC2 audio path is to the one in the TS-950SDX. The pre-amp circuit is likely the same (lurking on the IF unit somewhere) but the input path to the DSP and/or balanced modulator is probably different.
It's debatable whether or not it's worth it to do the mods though. All it will do is flatten out the bass response a little, and the difference may not be discernible to someone unless their receiver has better than normal bass response too. Also, on SSB, the DSP unit on the TS-950SD will still bottom out at 100Hz, so any added response you achieve below that frequency will be filtered out anyway. It may be worth it if you want to experiment with HiFi AM though (without the DSP enabled).
-Bill, N1GPT
Long story short, using the ACC2 port gives you less bass than using the front panel mic jack, unless you make a few modifications (i.e. changing out a few capacitors). This is a common design theme in most Kenwood HF rigs. Exactly what you have to modify varies a bit depending on the radio though. With the TS-870, it seems like there's just one cap that needs to be changed, which makes it a popular choice. With the TS-950SDX, there's about 5 of them. (The preferred method is to bypass the pre-amp circuits entirely.)
Unfortunately, I don't know offhand how similar the 950SD's ACC2 audio path is to the one in the TS-950SDX. The pre-amp circuit is likely the same (lurking on the IF unit somewhere) but the input path to the DSP and/or balanced modulator is probably different.
It's debatable whether or not it's worth it to do the mods though. All it will do is flatten out the bass response a little, and the difference may not be discernible to someone unless their receiver has better than normal bass response too. Also, on SSB, the DSP unit on the TS-950SD will still bottom out at 100Hz, so any added response you achieve below that frequency will be filtered out anyway. It may be worth it if you want to experiment with HiFi AM though (without the DSP enabled).
-Bill, N1GPT