ADC LED's not switched on or flashing, very few decodes

[Juergen Sturhahn]

After replacing the relays on my HL II the device worked without a problem (thanks a lot for the relays I have got from Mike and my friend Bernd, who replaced them very professional when I look at the pcb). After switching the radio on again now after some time at my second qth, however, there is a new problem I don't know how to fix:

- Powering on the HL II shows all LED's flashing as they should

- After connecting it to SparkSDR (version 2.033) the only LED's flashing or switched on are those at the ethernet connector and the Run-LED, at PTT the TX LED will also show up as switched on, both ADC LED's, however, even with RF Gain set to 48 db(maximum figure) remain dark (not continuously on or flashing as normally). There is no difference between RF AGC Mode off or max (but with max RF Gain is resetting to 30 db)

- Only very few signals are decoded with SNR figures pretty low

- noise floor is at -140 dB

- The virtual reciver settings only allow to open the General page, the ADC page is grey and cannot be opened

- switching the filters in the radio settings from hpf-lpf to no-rx-filters initiates a one time flashing (about 1 sec or less) of both ADC LED's. Switching back from no-rx-filters to hpf-lpf, however, will not show this one time flashing. The same effect can be seen when switching the filters to J16.

The same poor decoding could be seen when using Quisk.

Firmware version is 73, patch 2, board ID is 5, 4 receivers.

Any help would be very nice.

73

Juergen, DL8LE

[Steve Haynal]

Hi Juergen,

When no software is connected, is D5, the LED farthest from the ethernet port, on? 

https://github.com/softerhardware/Hermes-Lite2/wiki/External-Connections#onboard-leds-d2-d3-d4-d5

To eliminate any problems with the relays, do you see strong signal when connecting the antenna directly to RF3 on the HL2. Remove the N2ADR filter for this test. There is no connector installed for this, but you can temporarily connect a wire and then the wire to your antenna. This bypasses all relays.
https://github.com/softerhardware/Hermes-Lite2/wiki/IO#rear-io-strip-diagram

73,

Steve

kf7o

[Juergen Sturhahn]

Hello Steve,

the LED's in IDLE mode were working as shown on your link, i.e. D5 was on with no software connected.

I removed the filter board and made a direct connection from the inner conductor of the antenna cable to RF3 using a test tip of a multimeter. Every time I touched the RF3 D4 and D5 were flashing one time as described below, very low noise level of -140dB, no reception of any signal. By chance a made a short between GND and RF3 with the test tip and saw D4 and D5 flashing, without short only this one time flash.

In a next step I re-assembled the filter board again and touched RF3 at the connector between filter and main board with the test tip. All of a sudden D4 and D5 were on as required and I could see a couple of signals in the waterfall. I repeated this by touching the antenna connector of the filter board and saw the same. Using the HLII with SparkSDR in a normal way there is no problem any longer I could see, i.e. D4 and D5 on depending on the RF gain setting, normal decoding of the signals (and saw T31TT .. but no chance with 5 W only).

So it looks now as if there is a missing or intermittent connection on the main board which disappeared when pressing on the connector between filter and main board again. Might be there is a small micro crack in the small capacitor at RF3 or a bad solder joint, but I could not find it. I have tried to replicate the problem but no success. Luckily the HLII works now, even though it is disappointing not knowing why.  At least there is a way now where to look when the problem will show up the next time.

Thank you for your help! I hope there will be no need to contact you again because of this problem ...

73

Juergen, DL8LE

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[Steve Haynal]

Hi Juergen,

As you suggest, it sounds like the issue may be intermittent. Perhaps a component was cracked during the filter replacement. If you do discover which component, I can probably send you a replacement component.

73,

Steve

kf7o