vmts950sdx alc

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2e0pup
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vmts950sdx alc

Post by 2e0pup » Thu Nov 22, 2012 4:39 pm

hi all

i have read a few posts on various threads around the forum and i believe i should be able to get full drive from my sdx with no alc deflection or very little.

I am having probs with this, when i have little to no alc deflection im only getting 40-50 watts drive,

i can only seem to get full power with 3/4 to full alc deflection with occassional large peaks.

Is there a menu setting or something i need to do to get the sdx to run no or little alc deflection, or is it just a continuos balancing act lol.

Thanks in advance guys

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Post by Voodoo Guru » Fri Nov 23, 2012 4:58 am

Howdy!

Yes, you should be getting close to full output with just a few lights blinking on the ALC meter.

In order too actually see if you are putting out Full Power on SSB, you need a true peak reading meter. A regular RMS Meter will not show your actual Peak Envelope Power and the only way the 950sdx display will show it is if you have the Meter PEAK HOLD selected in the Menu.

You can make a rough check to see if the ALC Settings are close by putting the rig in the CW Mode, VOX Switch Pushbutton pressed OUT, FULL/SEMI Pushbutton pressed in, POWER Control full Clockwise, CARRIER control full counterclockwise.

Press the Transmit button and slowly increase the CARRIER Control clockwise to increase the power output. You should see the Power increase to full output and then you should see the ALC Meter start coming up. Full Power and the start of ALC should coincide with each other.


Hope this Helps,
Take Care,
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2e0pup
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Post by 2e0pup » Fri Nov 23, 2012 1:43 pm

thank you for that i am not at home at the mo, but i shall set it up according to your instructions and that makes sense too lol

i think i have had a few issue as im suffering with a very small amount of rfi, its hardly detectable, only on certain words, but i will continue to investicate :)

And this also causes alc to bounce around everywhere !!!!

thanks for the advice guys

Gotta love the SDX :D ESSB MACHINE

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Post by BillPaul » Tue Nov 27, 2012 12:21 pm

This is something that I've noticed as well. I have the peak-hold function turned on with my rig. I know that I can achieve 150 watts peak output with minimal ALC deflection -- the problem is it only achieves at that level very briefly during a voice peak. In other words, yes the peak power hits 150 watts, but the average power is a bit lower. I can see this with the wattmeter in my external MFJ antenna tuner. (I don't use the tuner much since I prefer my TS-950SDX's auto-tuner, but it provides a good way to switch between my two antennas.)

Now, if I turn on the TS-950SDX's speech processor, I can set things so that I achieve a much higher average output while still maintaining a fairly small amount of ALC action. I've never been able to achieve the same effect with just audio processing (I've experimented with various compression levels).

As an aside, I've also noticed that even with the 'peak' button on the MFJ engaged, it never shows 150 watts output either on SSB or AM. I suspect it's still showing RMS figures. On SSB, with the speech processor off, it typically shows about 50 to 75 watts output. With the speech processor on, this increases to a little over 100 watts. Now if I set the rig for CW or AM mode and adjust for maximum carrier, it will show 150 watts, which agrees with the output power meter in the rig.

The only problem is that with the speech processor on, the fidelity suffers. Engaging the processor unconditionally reduces the DSP's high cut frequency (the 'LPF' menu selection changes to 'Proc on' and stays that way until you turn the processor off) and for some reason the TS-950SDX's speech processor circuit is particularly noisy (it sounds buzzy and scratchy in the monitor). But it does do the job it was designed to do: by increasing your average output, it makes you much more readable during weak signal conditions. Most people who aren't using a hi-fi receiver probably won't notice the change in fidelity too much anyway, so sometimes it's well worth the extra boost to help you make a contact. In my case I find that my audio sounds a bit too muddy if I turn the processor on with my normal HiFi audio settings, so I have the low-cut filter on my mic pre-amp set up with about a 100Hz cut, and I flip this on at the same time I turn on the processor. If I want to really have that sharp nasally DXing sound, I'll set the 'HPF' menu on the rig to 200Hz instead.

Now, I would like to be able to achieve a higher average output (i.e. more punch) without incurring too much ALC action using just the audio processing gear, but like I said: I haven't found a good way to do it. I don't know if it's just that I'm not clever enough or if it's just not possible to achieve the same effect as the rig's speech processor. But at least the SDX is flexible enough that I can flip the processor on for a little extra oomph if I need it.

-Bill, N1GPT

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Post by DamonHammond » Fri Aug 30, 2013 12:43 am

Voodoo Guru wrote:Howdy!

Yes, you should be getting close to full output with just a few
led lighting blinking on the ALC meter.

In order too actually see if you are putting out Full Power on SSB, you need a true peak reading meter. A regular RMS Meter will not show your actual Peak Envelope Power and the only way the 950sdx display will show it is if you have the Meter PEAK HOLD selected in the Menu.

You can make a rough check to see if the ALC Settings are close by putting the rig in the CW Mode, VOX Switch Pushbutton pressed OUT, FULL/SEMI Pushbutton pressed in, POWER Control full Clockwise, CARRIER control full counterclockwise.

Press the Transmit button and slowly increase the CARRIER Control clockwise to increase the power output. You should see the Power increase to full output and then you should see the ALC Meter start coming up. Full Power and the start of ALC should coincide with each other.


Hope this Helps,
Take Care,
it helped me for sure.. I have facing similar problem and I hope I found solution for it.. Thankas

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Post by Voodoo Guru » Thu Sep 05, 2013 10:31 pm

Howdy Damon,

Welcome to the Forum!!
Glad to have you aboard.

We hope that the information here will help you.

Take Care,
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