Digital Still Needs Comp?

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  • Updated 6 years ago
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Thought I'd try my hand at RTTY with the 6500 this weekend. I made the cable described here in the group and used my trusty SignaLink USB. Jumpers were OK as they had been used on my Kenwood.

I found I still need 25% to 35% Comp to get full output power. Can anyone confirm this is normal with 0.16.4?

Thanks and 73,
Brad - N6SPM
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Brad - N6SPM

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Posted 6 years ago

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Mike - N1MD

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Brad,
I don't know if it is considered "normal" but I have found the exact same thing. We continue to get guidance about NOT using compressor and EQ when running digital but I definitely need Comp on at about 35% to get output.

The good news is that with ver 16 I have not needed the EQ.

I CANNOT wait for DAX!

Mike, N1MD
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Ed baker

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guys
your modem or signal link should be able to provide that .8 volt audio signal (Zero DB) to the input of the mike connection.

Mine does... No compression ,No +20 db pre amp. Just the tones at the correct input level.

And I do not exceed the 0 level set point. Or the ALC max .

If you are going to produce a 2 tone rtty signal Please don't add compression or EQ . Or you will produce a garbage RTTY signal.

IN SSB exceeding the limitations of the input will not make you louder , better, , just producing interference , garbage .
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Robert -- N5IKD, Elmer

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I installed JP3 on the SignaLink,
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Mike - N1MD

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Not using MIC on front of 6700 with SignaLink. Feeding Accessory jack on back of 6700. Level is not exceeded beyond 0. No EQ. No pre-amp. No excessive ALC.

In order to get rf power in this configuration, compressor has to be on.

Mike, N1MD
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Ed baker

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Compression adds audio. So. Your config. Is not producing that 0 db.

That's front back balanced. Mike anywhere you use audio input .
If your unit modem is producing the correct amount. And you adjust to the 0 level rig display
There is where you should be.

My rf. output can be adjusted from 1watt to 100 watts.
Saying this. Running. Rtty you better consider the duty cycle. And keep it within the rating. .
I run this flex 6500 no more than 30 to 50.watts rtty until I see a spec sheet on this radio
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Brad - N6SPM

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Thanks Mike, Good to know others see the same thing.

Ed, I understand where you are coming from. My SignaLink works just fine with my Kenwood - I have an A/B setup running now. Nothing unusual, no Comp, no pushing ALC, nada. It works fine. With the Flex, I can't even get 50W with the audio on the computer and SignaLink all the way up; it takes Comp. I too am not running anywhere near 100W. I bring Comp up until I stop seeing a change. I understand good RTTY operating procedure, and that is the motivation for the post - This does not seem right and the only difference is the Flex.

Robert, Thanks, I've had JP3 installed all along.

73
Brad _ N6SPM
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Ed baker

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JP3 – This jumper can be installed to increase the
SignaLink USB’s Transmit Audio Signal. With this jumper
installed, the SignaLink USB can provide up to 2Vp-p into
600 ohms. This should be more than adequate to drive any
radio to full power. Note that this is NOT needed for most
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Ed baker

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There is also a slider on your software when you select the signal link . That should be adjusted UP.
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Brad - N6SPM

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Thanks for the continuing support. As I said in the previous posts, JP3 has been installed all along. With it in, my Kenwood needs *very little* audio gain on the SignaLink and works great. The slider on the Windows Mixer (when choosing the USB Audio SignaLink uses) has always been at 100%.

Thanks,

73
Brad - N6SPM
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Brad - N6SPM

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Well, all things have an explanation, and I now have a partial one. I made up a cable (another one!) where I put a 600_ohm load across the Line 1 In and the Line 1 In Return. These are the signals wired to the Mic and Grd from the SignaLink. I instrumented it with my trusty old Tek 465, and lo_and_behold, 400mV P-P. I got about 500mV P-P without the 600_ohm load. Adjusting the POT on the SignaLink, or sliding the Slider in the Windows both attenuate the signal, but nothing makes it any bigger.

This AM I disassembled the SignaLink and double checked the Jumpers. I'm going to do it again and continuity check as well. If this provides nothing, I might have a problem with the SignaLink or possibly the generic Windows USB Driver.

Thank for the help.
73
Brad - N6SPM
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Ed baker

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glad your looking at the cause not the messenger.
.4 is 1/2 of what you would normally use.

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