Are PGXL PTT Outputs Open Collector Type?

Tim Blank

Given there is only 1 Tx Req input on the 6500, is the intent the PTT Output- A and PTT Output-B from PGXL Amp be connected in parallel? Should I assume the PGXL PTT-Outputs are Open Collector outputs and that is not going to damage the PGXL?

Tim - W4TME

None of those connections are used with the PGXL when the exciter is a FLEX-6000.  It uses the LAN interface so the only connections between the PGXL and the radio are the RF inputs and a single Ethernet connection to the LAN.

Tim Blank

But what if I select the pgxl PTT source to be rca?

Tim Blank

Similarly how are the PTT key inputs of the PGXL supposed to be connected to the 6500? There is only one logical key output request? Are the pgxl rca’s suppose to tied together as well? I know the lan is the preferred connection method but some of us that use sequencers for eme work need to utilize the rca keying interface. Guidance about this would be appreciated....or do I need to open a service ticket?

Tim - W4TME

You do not use the RCA PTT with a FLEX-6000.  Keying and band changes are handled using API commands over the Ethernet connection.  You can assign each port on the amp to a separate antenna connector on the FLEX-6000

And the PGXL is an SO2R amp, meaning the A and B sides are independent of one another,  You do not tie the PTT together.  You use two traditional radios.

Use the radio TX Relay for your sequencer triggering, not the amp.

Tim Blank

I figured this out...the solution I settled on was to use the TX1 and TX2 outputs configured to map the TX output to the antenna corresponding to the input. So if 160-10m antennas are on ant1 and 6m antenna is on ant 2, then TX1 is configured to be active on 160-10 and TX2 is configured to be active only on 6m. TX1 output then connects to PTT-A in and TX2 connects to PTT-B in on the PGXL. Still not sure how to deal with the PTT-x outputs. Maybe just leave them unconnected? Seems risky but that maybe the price of using the rca connections.

David Decoons, wo2x

As Tim stated, the Ethernet connection will handle the PTT and TX Req connections via IP. There is no need to use the PTT connectors with the Flex, it just adds unnecessary cabling.

Dave wo2x

Tim Blank

Hi Mike, I think you missed my point. I plan on using the PGXL for 6m EME work. This requires an external tower mounted preamp and sequencer to insure proper preamp power and PGXL keying and unkeying. Until someone comes along and implements sequencer functionality in smart sdr, an external device is required....

Tim - W4TME

I think you missed my point.  You really don't want to use the amp for triggering your preamp.  I believe that if you read section 38.6 in the SmartSDR Software User Guide v3.x regarding how the TX Relays work, paying particular attention to the paragraphs on timing, that you can easily accomplish what you want to do. without having PTT "cascaded" through the PGXL whereby eliminating a failure point.

Tim Blank

I think you are misunderstanding what I am saying...I am not using the amp for triggering the preamp. The sequencer controls the timing of applying power to the remote preamp and triggering the pgxl to avoid destroying the preamp ( hot switching). No cascading involved.