Did I Likely Already Damage U6 (5P49V5923)?

[Brian McCarthy]

I have been working my way through the interfacing steps for using my HL2 with transverters for microwave work. I tried to feed 10MHz into CL1. My configuration is:

Hardware

Hermes-Lite 2.0-build9

N2ADR Filter Board Rev E5b9 (or E569)

WA2T HL2+ AK4951 V4.0 Companion Board

Software

Thetis v2.10.3.4 x64 (01/07/24) (FW v7.4.2 Protocol 1) HL2-Beta3 (MIOBOT)

Gateware - 74p2 - as linked for V4.0 + board at https://www.hermeslite2plus.com/p/hl2-gateware-download.html

The GPSDO 10MHz source is direct from the output of my HP Z3801. I had an intermittent BNC cable that I initially tried to use. Eventually, I got a good cable connected. When I click the check box of "Ext 10MHz (CL1 Input) as shown below, all of my receive goes away and the HL2 behaves like the clock is missing.

While trying to troubleshoot the situation, I ran across a post that said the 10MHz input level is critical (https://groups.google.com/g/hermes-lite/c/ho_R7sV327U/m/f63lkN6PAgAJ.) I got a scope onto the output of my source and measure it as 4.5vpp. I put a 6db attenuator inline, measured about 2.3vpp, and tried again. Still no receive after checking "Ext 10MHz". Receive returns upon unchecking.

So - Did I Likely Already Damage U6 (5P49V5923)?

Are there some other tests I can do?

If U6 is really damaged, I do not have the tools or the practice to replace it myself. Are there any repair options in the US?

Thank you,

Brian

NX9O

[Brian McCarthy]

Good news, I did not damage U6. Bad news, I didn't carefully read the front panel of the HL2. I had swapped the leads of CL1 and CL2 into the HL2. It may have saved me from damaging U6. From the U6 5P49V5923 datasheet:

I would not have been doing myself any favors by stuffing 4.5vpp into CL1. Instead, I was putting the 4.5vpp into the output channel of CL2, and I did not manage to kill that output channel.

A shout out and big Thank You! to Mike, K7MDL, for responding to me directly. I now have the 10MHz reference input fed with my GPSDO, but with a 6db attenuator inline. I also identified that the CL2 output is much more of a square wave channel. I'll have to be careful about how or if I use that CL2 output.

Brian

NX9O