2MLDPA doesn't power up

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  • Updated 5 months ago
Just received my 2MLDPA from q5signal.
It is configured for remote operation (DC power, LNA, transmit) and for Common RF output.

It is not powering up - no LEDs are on and fan is off.  I measured 14.4 v on the power connector.

Is there an interface cable wiring diagram available?

I have connected the DC power cable to a DC power supply, the accessory cable USB to one of the flex 6700 USB ports, the trans BNC to the flex xvtr BNC, and the RX/ANT N to my 2m antenna.

Under USB cables settings, I have:
Name: 2MLDPA
Serial: FT2HDTPJ
Cable Type: LDPA
Band: 2m
Preamp: Internal

With a single RX slice:
The transmit and receive antennas are both set to XVTR.
The frequency is 146.52 MHz and the modulation is FM.
DAX reports TX and RX 1 are both streaming.

Do I have the correct cable connections and SmartSDR configuration?

Flex-6700 info:
Serial: 3218-9797-6700-0100, Max Licensed Version: v3, Radio ID: 00-1C-2D-02-0E-A5,  Radio Internet: NOT Available, Radio Firmware: v3.0.27.131
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Posted 5 months ago

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Photo of Michael Walker

Michael Walker, Employee

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Q5 answers emails at all hours. 

They don't monitor this group, but I would email right away.  


Photo of Doug


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Thanks - did that.  Also hoping for a reply from someone who is using this amp with remote config and perhaps SmartSDR v3.0.27.
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John - WA7UAR

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So with my unit I ordered the “remote control” option which includes an accessory port plug in — with one line going to a USB dongle (that plugs into the back of the Flex) and another wire that I soldered to an RCA type jack that I plugged into one of the TX female ports on the back of the Flex. Both are needed. The SmartSDR software is told about the USB Cable type (LDPA as you mentioned) but it is my understanding that the RCA jack carries the Flex signal back through the 2MLDPA accessory port which triggers the device to power on.

It receives its power-on signal as long as the Flex is showing a 2m frequency. And when it is powered off it will default to pass-through any other IF signal along to another amp (for example the Q5 440MHz amp.)

This is all from memory at the moment but I think this is correct. There is no “power switch” because power is applied (via an internal relay) only when a correct frequency is entered. It was working using 2.4.9 and it is still good for me with 3.1.7.

Can someone give a better explanation for Doug?
Cheers to all.
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This can be closed.
Turns out the configuration I listed originally is correct for this (current) version of the amplifier.
The problem was a bad slot on a Powerpole connection block.
After moving to a different slot, the power LED came on before the 6700 finished booting.
The amp meets the power output spec and the FM audio sounds fine.