10V reference voltage source

The work with lithium cells called for voltages to be measured with an accuracy of at least 50 mV, for instance to prevent overcharging of the cells.
Over the years, a number of multimeters have accumulated in my shack – with quite different quality. Now the question was: which meter should I trust? For some of the devices, not even information about their accuracy was available any more.

Weiterlesen

DM/BW-064 – Heersberg – 964m (2)

Abstract:

June 21st, 2020, 08:50 – 11:30 UTC
My second activation of Heersberg.

Wx: Sunny, few clouds, temp about 18°C
Walking time: 25 min up, 20 min down
Ascent/ descent: Approx. 60 vertical metres

Rig: KX3 / 10W, 2.9Ah AGM battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner as inverted L on a  6m squid pole.

Condx on all bands were good. On the higher bands sporadic E was present which allowed many short skip contacts into EU. k = 1, SFI = 68

1 CW QSO on 60m – 1 x S2S
1 SSB QSO on 60m – 1 x S2S
24 CW QSOs on 40m – 6 x S2S
1 SSB QSO on 40m – 1 x S2S
28 CW QSOs on 30m – 5 x S2S
21 CW QSOs on 20m – 3 x S2S
4 SSB QSOs on 20m – 4 x S2S
13 CW QSOs on 17m – 1 x S2S, 1 x DX

Highlight:
22 summit to summit QSOs with more than 100 S2S points 🙂

Lowlight:
None

Weiterlesen

Delta Loop for the 40 metre band

A delta loop antenna – especially for the 40 metre band – is not exactly suitable for SOTA. It is huge and requires a lot of space. Furthermore the set up is time-consuming.
Nevertheless I’d like to show this design here because:

  • During sunspot minimum 40 m still offers the opportunity to work a lot of DX.
  • The delta loop provides the required take off angle to work the DX.
  • Sometimes space (and time) don’t matter.
  • It’s fun building it 😉

A possible application could be intercontinental S2S events.

During our DX-pedition (Link) to the Principality of Liechtenstein in Sept. 2013. DL4AAE worked hundreds of JA’s on 20 metres with this antenna and 100 W output power.
Here is the Link to the 20 metre version of the delta loop.

loop1
Delta Loop for the 20 metre band on HB0/Li-004, Augstenberg, 2359m a.s.l.

Weiterlesen

DM/BW-014 – Weisstannenhöhe – 1190m

Abstract:

June 13th, 2020, 13:30 – 14:00 UTC
My first activation of Weisstannenhöhe.

Wx: Partly cloudy temp about 18°C, few raindrops on the way back
Walking time: 30 min up, 20 min down
Ascent/ descent: Approx. 230 vertical metres

Rig: KX3 / 10W, 2.2Ah LiPo battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner as inverted L in a tree.

Condx on all bands seemed to be average at best. But this was probably because my QTH was in the middle of a forest. There were only few RBN spots. k = 1, SFI = 71

7 CW QSOs on 20m
7 CW QSOs on 30m
10 CW QSOs on 40m

Highlight:
Nice chat with the owner of a biogas plant.

Lowlight:
Not a single S2S- QSO.

Weiterlesen

DM/BW-002 – Herzogenhorn – 1415m

Abstract:

June 12th, 2020, 13:50 – 14:40 UTC
My first activation of Herzogenhorn.

Wx: Sunny, only few clouds, warm
Walking time: About one hour but no record is available.
Ascent/ descent: Approx. 230 vertical metres

Rig: KX3 / 10W, 2.9Ah AGM battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner as inverted L on a 6m- squid pole.

Condx on all bands were good. The number of QSOs was average. k = 1, SFI = 71

10 CW QSOs on 20m  – 1 x S2S
13 CW QSOs on 30m
9 CW QSOs on 40m – 1 x S2S

Highlight:
Meeting DM3FAM at the summit.

Lowlight:
None

Weiterlesen

DM/BW-001 – Feldberg – 1493m

Abstract:

June 12th, 2020, 10:30 – 11:10 UTC
My first activation of Feldberg.

Wx: blue sky with no clouds at all, pleasant temperature
Walking time: approx. 60 minutes up, 0 minutes down as we took the chairlift
Ascent/ descent: approx 250 vertical metres

Rig: KX3 / 10W, 2.9Ah AGM battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner as inverted L on a 6m- squid pole.

Good condx on 40m for central EU with loud signals and a small pile- up.
30m was disappointing with lots of QRM from the transmitting stations nearby.
k = 1, SFI = 71

23 CW QSOs on 40m – 5 x S2S
3 CW QSOs on 30m – 1 x S2S

Highlight:
Magnificent view of the Swiss Alps: Eiger, Mönch Jungfrau,…

Lowlight:
Lots of QRM on 30m.

Weiterlesen

DM/BW-015 – Hochfirst – 1190m

Abstract:

June 11th, 2020, 08:50 – 10:00 UTC
My first activation of Hochfirst.

Wx: Overcast with sun from time to time, temperature approx. 14°C
Walking time: Zero, Hochfirst is a drive-on location
Ascent/ descent: almost 0 vertical metres

Rig: KX3 / 10W, 2.2Ah LiPo battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner as inverted L on a 6m- squid pole.

Condx on 30 metres and 40 metres were good with loud signals from all over EU and a small pile- up on each band.
k = 1, SFI = 71

31 CW QSOs on 40m
2 SSB QSO on 40m – 2 x S2S
32 CW QSOs on 30m – 1 x S2S

Highlight:
65 QSOs in less than 70 minutes net. operating time
One of the QSOs with DX.

Lowlight:
The QSD when operating the paddles with my left hand persists.

Weiterlesen

DM/BW-089 – Farrenberg – 820m (5)

Abstract:

May 31th, 2020, 10:10 – 12:50 UTC
My fifth activation of Farrenberg.

Wx: sunny with occasional clouds, temperature approx. 18°C
Cycling time: approx. 90 min. up/ 60 min. down
Ascent/ descent: approx. 900 vertical metres/ 24 km one way

Because of the CQ WPX CW contest taking place at the same weekend I tried to avoid the contest bands.
Condx on the higher bands were dominated by sporadic E with loud signals from all over Europe. 30m and 40m produced loud signals and a good pile- up.
60m was disappointing with no callers at all. k = 1, SFI = 71

Rig: KX3 / 10W, 2.9Ah AGM battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner as inverted L on a 6m- squid pole.

10 CW QSOs on 12m
5 CW QSOs on 17m
1 SSB QSO on 20m – 1 x S2S
17 CW QSOs on 30m – 3 x S2S
13 CW QSOs on 40m – 1 x S2S
1 SSB QSO on 40m – 1 x S2S
1 CW QSOs on 60m – 1 x S2S
1 SSB QSO on 60m – 1 x S2S

Weiterlesen

Balcony On The Air

Since the end of March I was more frequently QRV from our balcony. This was possible because we had unusual warm and dry weather. Also, I had more time due to the Corona crisis: As we all know, many events were cancelled and short-time work became effective.

2020-05-27 18.16.45

The “ operator’s workplace “ is located on the bench next to the terminal box of my 40 metre long wire (not in the picture, you only see the board on which it is mounted). A short piece of coaxial calbe connects the KX3 to the antenna. The built-in ATU provides the necessary matching. The KX3 is powered by a 17 Ah AGM battery (brown wooden box), which in turn is powered by a 10 watt solar cell with a PWM regulator.

Usually I am on the air from late afternoon, when the D-layer absorption decreases and the 60-metre band comes to life. When sporadic-E is present, I like to switch to the higher bands, which are now – in times of sunspot minimum – rather poorly used.

With a maximum output power of 10 watts and a long wire, no miracles are to be expected. But it works all across Europe and sometimes remarkable contacts can be made that will remain in your memory.
Moreover, it’s incredibly relaxing to be out in the open with the world’s greatest pastime.

DM/BW-094 – Kornberg – 779m (2)

Abstract:

May 20th, 2020, 10:45 – 12:15 UTC
My second activation of Kornberg.

Wx: overcast with occasional sunshine, temperature approx. 18°C
Walking time: approx. 20 min. up/ 10 min. down
Ascent/ descent: approx. 110 vertical metres

Condx on 40m were good with lots of strong signals from central EU. But also QSB on signals from stations further away. On 30m a single (!) station responded to my CQ and only towards the end I managed to log a second call sign. 20m surprised with sporadic E and strong signals from central EU. k = 1, SFI = 70

Rig: KX3 / 10W, 2.9Ah AGM battery, Palm Pico Paddle
Ant: 22 m end fed wire with QRP L- Tuner in a tree.

9 CW QSOs on 20m
2 CW QSOs on 30m – 1 x S2S
34 CW QSOs on 40m – 5 x S2S
2 SSB QSOs on 40m – 2 x S2S
1 CW QSO on 60m – 1 x S2S

Weiterlesen