DEMI 2MLDPA On/Off/Bypass

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  • Updated 9 months ago
I am trying to find the On/Off/Bypass control in SmartSDR1.10 for the 2MLDPA.  I have found the preamp on/off.  The DEMI literature says that it can be turned on/off/bypassed as a remote function.  I called them and they just pass the buck saying Flex is doing the software and they are just hardware.  Can anyone whom has a DEMI 2MLDPA remote help or can someone from Flex comment?
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John-K3MA

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Posted 2 years ago

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Tim - W4TME, Customer Experience Manager

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This is a previously reported defect with setting the preamp state.  It has been placed in our bug tracker as defect #4302.
(Edited)
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David-N5PSM

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I would also like to know.....my (DEMI 2MLDPA) is on order....
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Ken Gilcrest

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I for one would really appreciate it if someone could post something about running the 2MLDPA with the new software update. There was a thread and the first day the software came out, the guy said he figured it out and the thread was closed but he never posted any of the information about what he did; just that he figured it out.   
I admit that I haven't spent a lot of time working on this issue. It seems like ever since the latest update, I have been sidetracked with something else. So, it would be nice if someone posted a how-to guide for the 2MLDPA. 
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George Fenwick

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My 2MLDPA seems to work fine with 1.10, but for the preamp not staying on once turned on. (I've reported this and it is a logged bug). "On/Off/Bypass" control is simply a function of selecting 2M or not. The LDPA turns on when 2 M is selected, and turns off and goes into bypass when 2M is de-selected. Nothing else to tell. No other buttons needed.
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Ken Gilcrest

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Ok, so you supplied power and an antenna to the 2MLDPA and plugged the USB cable into the back of the radio and it works ?
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Burch - K4QXX

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I was the one who posted I had figured it out.  I was surprised that the thread was closed?  Not sure what that is about.  Once you supply power and plug in the USB cable for the 2MLDPA, you click on the settings menu and then USB cables.  You will then see the cable listed.  Double click on the entry and then you can name the cable and select the Cable type (in this case, LDPA).  Once this is done, when you select 2 meters from the band menu, the amp powers on.  I have the same issue as George as I have to select to enable the preamp each time I restart SSDR.  The premap setting is also under the Settings, USB cables and then select the amp. 
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Ken Gilcrest

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Thank you very much for the help.  It works !!!!!

"select the Cable type (in this case, LDPA)"  
This is what I was missing. I was making this WAY more complicated that it actually was. 
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Burch - K4QXX

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Great!  Glad I could help.  So far the amp seems to work very well.  Now we just need a band opening.
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Ken Gilcrest

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I am now playing around with all kinds of stuff. I worked a couple guys on 2m FM. I am running it on APRSIS for APRS. I am trying to configure Soundmodem so I can use this for Packet but I am still figuring out how to get PTT.  Will move onto weak signal stuff gradually.  One other thing I am going to mess with later today is using this on 2 meters D-Star. 
(Edited)
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G4YDO

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i don`t believe i have a usb on my demi 2mldpa?
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Burch - K4QXX

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You have to order it with the remote option.  It's available on their new model that's only been out about a month or so.
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Mike - VE3CKO, Elmer

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I do realize Tim acknowledged this and is in the bug tracker as defect #4302. I just want to fully explain what I'm seeing with my 2MLDPA (ordered from DEMI for remote operation), so it may assist developers:
  • If the LDPA is off it will turn it on when opening the 2m band but it does not shut off when panadapter is closed.
  • Under Settings, there is a 2MLDPA cable and the Type "LDPA" must be selected. Double clicking the 2MLDPA in the USB Cable menus brings up "USB LDPA Cable 2MLDPA (serial #) Edit".
  • With the Preamp "enabled", using the 2MLDPA USB Cables turns on 2MLDPA when disabled, turns off 2MLDPA when enabled. Green LED is on/off accordingly.
  • With the Preamp "disabled", using the 2MLDPA USB Cables turns on the LNA when disabled, turns off LNA when enabled. I hear relay clicking toggling LNA on/off and do see the noise floor change.
I have verified accessing the USB Cables on the Maestro, the 2MLDPA behaves in the same manner. Since the MENU totally blocks the whole panadapter display, I can hear noise floor change when toggling the LNA.

Since I got the 2MLDPA, only once, my 6700 lost connection over night and locked up. When I went into the shack in morning I also discovered the 2MLDPA transmitting. I rebooted the 6700 and hasn't happened since.

I should also mention the  frequency of receive and xmit on 2m SSB with the 6700 is wrong and cannot be calibrated yet, this is a known defect (#3333). To get around this bug, each time I go on 2m I must set the RIT to 500 and XIT to 300 manually on each slice. These settings do not get saved into memory.

With new innovative technology both from FRS and in co-operation with 3rd parties it's an exciting time to be a series 6000 owner. SmartSDR has made some great progress and we always want the bugs that effect us and features we want to be done first. I have no idea when defect #3333 was found and what priority it may have on the to-do list but as I said in another post, I'm hoping because more 6700 users are buying the 2MLDPA, this will get prioritized. Recently upgraded to the 6700 and with the price tag certainly didn't expect 2m transmit/receive frequency to be inaccurate, but I am appreciative FRS immediately acknowledged it as a known issue. .
(Edited)
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W9AT

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Hi Mike,

Is this still an issue in the current version of SmartSDR v1?  Is it an issue currently in SmartSDR v2?

Thanks much!

Mark W9AT
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Justin - KL2D

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Hi Mark - FWIW, my 2MLDPA is working great with the latest version of V2, on/off preamp all no issues. I’m successfully using it with a DEMI 70cm Transverter for sats. I’m also using an auto switching rig runner to control the power for the Transverter, so when the LDPA comes in so does the xvrtr. It’s all working great together, and when I’m working HF and no 2M slice open it all shuts off automatically.

Hope that helps,

Justin
KL2D
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W9AT

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Thanks Justin!

Mark W9AT