Flex 6700 with DEMI 2MLDPA for EME

Mike Presnell

Looking for some tech assistance from folks who have been operating their Flex for EME.
I will preface everything by saying i have NOT yet attempted to operate. I do not want to **** the preamp before I ever get started.

I have a Flex 6700, DEMI 2M LDPA, BEKO 1.5K Amp,  BEKO Mast Mounted PreAmp

I have the BEKO PreAmp wired to receive 15VDC from the BEKO AMP, it has a built in sequencer to turn off the power to the preamp before it keys the amp.


So, I was thinking that my Flex will key the PTT to the BEKO Amp.  The BEKO Amp will turn off the power to the preamp, and then it's PTT Out will key the DEMI 2M LDPA.

Will this work?  Is the low level drive of the 6700 enough to **** the mast mounted preamp since it will be keyed before the BEKO?

Thoughts/suggestions?

Respectfully,
Mike
WB0O

WA2SQQ

I’ll defer the final response to someone else, but I will offer one piece of advice. Use a solid state buffer device between your Flex and anything you connect to the TX1-3 outputs. If you damage the TX outputs, you’re looking at a trip to FRS to replace a $2 part. I have one such buffer with 3 relays that isolates all 3 outputs. I think it cost be about $12.. The relays can safely switch 10A.

EA4GLI

Add 100ms delay to the tx just for safety, you can easily do that on the menus of the 6700.

Mike Presnell

Thanks for the advice.  Is there any particular device that you recommend?  Which are you using?

paul

Larry Loen WO7R

I would figure out what the delay actually is. Our setup (I work with a team) ended up needing 350 ms delay after PTT was off before it was safe. With JT65, a substantial delay hurts nothing anyway.

Erika - KØDD

Mike Presnell

Thanks Paul, I will take a look at the ARB704!   The BEKO preamp specs states that it handles 2.0K … although the label on the case shows 2.5K  It's supposed to work well with my BEKO 1.5K amp which is supplying the 15VDC.   I should be able to get everything in sequence without a separate "sequencer" since that function is built in to the BEKO Amp.    My only concern is,  IF I ever messed up the delay setting in the Flex settings,  is the low-level drive of the 6700 enough to **** a mast mounted preamp?   I guess I need to check the 6700's specs, to see how much that drive is, and ask BEKO,   but I thought I would ask on the User Board here as well, since there are a lot of experienced users like yourself here.

Ha Gei

WA2SQQ

https://www.ebay.com/itm/1-16-Channel-5V-12V-Relay-Module-Board-For-Arduino-Raspberry-Pi-ARM-AVR-DSP-PIC-/163629279846 Just select how many channels and whether you want 5 or 12v to run the board.

KF4HR

KF4HR