peaks at 65

[John Harlow]

I received my hermes lite 2 today. I am quite impressed with the shipping speed (about a week) and the product quality. After drilling a single hole I was able to assemble my unit in just a few minutes.

I hooked it up to a power supply and lan adapter port on my usb expander. I launched powersdr and it was immediately recognized and functioning. Wow that was easy!

However I noticed something strange, the spectral display showed large silent peaks at intervals of 65. The metric changed with the band. For example on 160 meters it was 65 khz. On 80 meters it was 650 khz, etc. Very odd.

I took it all apart, did a bunch of poking and prodding, examined every connection on the board and all looked well.

Then it dawned on me it - could it be the power supply? So I tried another and problem solved.

I felt compelled to post this as I could see it happening to others and searching for this symptom didn't return any results.

Now on to getting a suitable antenna set up. The receiver seems kind of weak as I can't get any local AM stations unless I set up a fairly long wire running outside, and even then they are faint.

[Alan Hopper]

Hi johnh,

good to hear it is working and welcome to the group.  Weak am reception can be caused by the filter setup, maybe you have the highpass filter enabled.

73 Alan M0NNB

[John Harlow]

Thanks for that tip. Where is this set up in powersdr? I have the N2ADR board and J16 receive pins set up in the Hermes Ctrl per the youtube guide, is there another location?

[Steve Haynal]

Hi John,

The video filter settings should be correct. Also check if your LNA setting is in the +12 to +20dB range. That should be covered in the video. If your are not already, Reid's version of PowerSDR will work better for the HL2:

https://github.com/softerhardware/Hermes-Lite2/wiki/Software#powersdr

73,

Steve

kf7o

[John Harlow]

Thanks Steve, I installed Reid's latest beta and it works great so far. Also I found that the HL2 front end is kind of susceptible to PS noise. I ended up using analog supply as all the switchers I have polluted the front end pretty bad. I might try adding more bypassing, choke or possibly a faraday contraption around the PS input.  It would be nice to be able to use a standard low cost 12v switcher.

[Steve Haynal]

Hi John,

In the past, most switching noise people see on the HL2 is not coming in through the HL2 power connector, but is radiated through your house wiring and picked up via the sensitive HL2's antenna. You'll probably see this noise on any decent radio if the suspect switching power supplies are nearby and delivering current to a load. You can test how the noise is entering the HL2 by removing the antenna or connecting a dummy load with very short/no coax. Check for spurs and general rise of the noise floor using different power supplies. There are two spurs in the 1.8MHz range from the HL2's internal switching regulators. These spurs usually can't be seen above the 160M noise floor. The HL2 has a unique feature to control the switching regulator frequency and can move the spurs if they are problem.

The EPS-3 ADP-36KR A does a pretty decent job for an inexpensive switching power supply.

73,

Steve

kf7o

[Robert Benedict]

Some years ago I put this up in my shack as a central source of clean, protected power. It's designed for home audio, but also does a good job for HF. This is a well built piece of hardware.

Furman M-8X2 Merit Series 8 Outlet Power Conditioner and Surge Protector

• AC noise filtering reduces RFI/EMI, Spike & surge protection ensures equipment stays safe & power stays clean,
• 15 amp rating with circuit breaker and "Protection OK" Front Panel Indicator to let you know that your equipment is being protected
• 9 Total outlets: 8 rear panel outlets (including 3 with "wall wart" spacing) and 1 front panel convenience outlet
• Filtration rating greater than 23 dB, 200 Khz to 10 Mhz, perfect for instrument rigs, home recording, DJ equipment, pro audio rigs and home entertainment systems
• Furman's AC noise filtering reduces RFI and EMI interference to deliver a cleaner sound without pops, crackles and the local radio station coming out of your amp

https://www.amazon.com/gp/product/B003BQ91Y6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

   73

     Bob   KD8CGH