Topics

Elad duo and wsjtx

 

evening 

I’m set up for wsjtx and noticed I have no alc,
im new to duo and yahoo groups.
im sure this has been asked a million times, and I don’t know how to find the answers yet

how do u adjust ya output, is it in dB? I’ve set mine at 18dbm, or has this nothing to do with it, and I’m on one😂

many thanx
iain
MM6IXE

Neil Smith G4DBN
 

Set the DUO to show TX power, then send a constant @1000 tone from WSJT-X and adjust the power slider until you get a 3dB drop in output power for a 3dB drop in WSJT-X level.  Then put the power back up by 3dB and you will be pretty close to the right level for max power.  Make sure you are running Fake-It split in WSJT-X.

ALC doesn't actually matter much with "constant carrier" modes like FT8 or JT9, the only issue is a potential wideband splat at the initial startup, as there is no soft-start in WSJT-X, but if you ensure you are in the linear range of the PA, you won't have to worry about any additional weird phase distortion effects.

This isn't a Yahoo group (thank goodness!) so you can search the archive very easily.

Just click on the link at the bottom of every mail and it takes you to the groups.io page for EladSDR and you can use the search tool for the whole archive from there.

Neil G4DBN


On 10/09/2019 20:00, MM6IXE wrote:
evening 

I’m set up for wsjtx and noticed I have no alc,
im new to duo and yahoo groups.
im sure this has been asked a million times, and I don’t know how to find the answers yet

how do u adjust ya output, is it in dB? I’ve set mine at 18dbm, or has this nothing to do with it, and I’m on one😂

many thanx
iain
MM6IXE

 

Morning Neil

Sorry I’m not quite understanding that, do you mean send a carrier at 1watt from duo, with the power forward selected 

Do u mean the power slider on right hand side wsjtx, I’ve never noticed that until now

i can run fake it split😁

iain
MM6IXE

Neil Smith G4DBN
 

This ius just the way I do itg, there may be other ways.

Set the DUO to whatever power you want to use.  Set the display to show output power (or use a power meter).

I set mine to MAX and used an HP power meter.

What we need to do is make sure that WSJT-X is producing just enough audio to get you to full power and no more. 

Open up the Sound Control Panel in Windows and identify the FDM-DUO Line Playback device.  Click on it, then on the Properties button.  Select the Levels tab.

In WSJT-X, set the slider to max power.

Hit the Tune button in WSJT-X. That will give you a 1000Hz tone.

In the Windows Sound Line Properties box, slide the volume control until you see the output power drop by 1dB or so.  For me, thatg is at around 50 on the slider.

Now go to WSJT-X and drop the output power slider to -3dB (you might have to go to -3.1dB) and see if the output of the DUO drops by the same amount.  It probably won't, mine dropped by -2.6dB.

Drop it to -6dB and see what the DUO says, should be almost 6dB down.

My output on 28MHz in MAX is aboutr 5.5W where it is linear enough.

Short version, just drop the Windows device leve until the powere drops by 20% and you'll be close enough.

Neil G4DBN



On 11/09/2019 11:17, MM6IXE wrote:
Morning Neil

Sorry I’m not quite understanding that, do you mean send a carrier at 1watt from duo, with the power forward selected 

Do u mean the power slider on right hand side wsjtx, I’ve never noticed that until now

i can run fake it split😁

iain
MM6IXE

 
Edited

Evening Neil

what a knowledgeable man. I’ve done as u said and all fired up great
just trying it now for my first ft4,8 contact on the Duo

are u using Cat or RTS?

many thanx and I’m happy with your way👍

Iain
MM6IXE

should I also be thinking of a small 12 volt fan for airating the duo during digital ops?

Antony Watts
 

HI

just seen your email..

You have to set up BOTH CAT for frequency control and RTS for PTT. I operate FT8 most of the time due to poor antenna here (60cm indoor loop!)

73

Antony
M0IFA

On 11 Sep 2019, at 16:47, MM6IXE <@MM6IXE> wrote:

[Edited Message Follows]

Evening Neil

what a knowledgeable man. I’ve done as u said and all fired up great
just trying it now for my first ft4,8 contact on the Duo

are u using Cat or RTS?

many thanx and I’m happy with your way👍

Iain
MM6IXE

should I also be thinking of a small 12 volt fan for airating the duo during digital ops?

Neil Smith G4DBN
 

Hi Antony, if you use the new Hamlib drivers for the DUO, you no longer need to use RTS for PTT, CAT PTT *does* work fine now.

I just stick to the old way because I'm like that.  The old way was necessary because of a programming race condition bug in the TS480 Hamlib.  That bug is *STILL THERE* in the TS480 so RTS PTT is mandatory if you won't move to the new DUO driver in wsjt-x etc

Neil G4DBN

On 11/09/2019 18:35, Antony Watts via Groups.Io wrote:
HI

just seen your email..

You have to set up BOTH CAT for frequency control and RTS for PTT. I operate FT8 most of the time due to poor antenna here (60cm indoor loop!)

73

Antony
M0IFA

On 11 Sep 2019, at 16:47, MM6IXE <@MM6IXE> wrote:

[Edited Message Follows]

Evening Neil

what a knowledgeable man. I’ve done as u said and all fired up great
just trying it now for my first ft4,8 contact on the Duo

are u using Cat or RTS?

many thanx and I’m happy with your way👍

Iain
MM6IXE

should I also be thinking of a small 12 volt fan for airating the duo during digital ops?