630m QRP WSPR (Tuesday)

 My 10mW ERP 630m WSPR from the earth-electrode "antenna" was turned on at 2220z.

UPDATE 2225z: 2 stations have spotted me so far.

NanoVNA and TinySA

These amazing pieces of test gear bring some otherwise very expensive test equipment within the reach of radio amateurs. Years ago, these would have been out of my price range. I now have both.

By King's - NOT amateur radio

At the end of January there are few punts on the River Cam. These Canada Geese have the river almost to themselves.

630m QRP WSPR overnight

My 10mW ERP from the earth-electrode "antenna" in the ground was left on overnight. In the end, 21 stations spotted me.

10mW ERP on 10m WSPR

After breakfast, my priority is to make a 17dB attenuator so I can try WSPR at 10mW ERP on 10m today. This is to simulate this power in the Es season in the 8m ISM band without a licence. I have the coax, but have to find the resistors.

UPDATE 0930z:  Attenuator made and added right next to FT817ND on 500mW setting, so WSPR power now very close to 10mW ERP.  WSPR TX set to 50% TX. Already spotted by 2 stations on first TX burst!

UPDATE 1640z:  My FT817ND  is on the lowest (500mW) setting. Also, I have a 17dB pad within about 10cm of the FT817ND, so the output is about 10mW. With about 1dB coax loss the ERP is about 10mW or less. Despite this, I have been spotted by 14 unique stations. This is to simulate 10mW ERP on 8m, which is the legal 8m ISM legal limit in the UK without a licence. It is my view that anyone in the UK may legally beacon on the 8m ISM band as long as IR2030 is met.

UPDATE 2236z:   Using the FT817ND, I was 50% of the time on RX today. Despite the 17dB pad in the antenna line at the rig end I still spotted 99 stations!! The furthermost was PY2FXE (9593km).

WiFI HaLow - NOT amateur radio

Increasingly, the Internet of Things (IoT) is driving new ways of doing Wi-Fi. One standard (new to me at least) is 802.11ah which has been around since 2015. This operates around 900 MHz with a range of up to 1km. It will be interesting to see if there are spin-offs for amateur radio.

Sunspots - Tuesday Janauary 30th

 Solar flux is 140 and the SSN just 48. A=9 and K=3.

Oscar 100 narrowband transponder

Every few weeks I take a peek at activity levels on the geosynchronous satellite. I do this by looking at the webSDR at Goonhilly Down. My impression is this is well underused.

See https://eshail.batc.org.uk/nb/ .

Attenuators

To get to 10mW I shall probably run my FT817ND at 500mW, and add an attenuator right on the output of the rig. The attenuation needed will be 500/10 i.e. 17dB. There are several calculators on the internet. Using the FT817ND will allow me to declare the correct output power.

See https://www.everythingrf.com/rf-calculators/attenuator-calculator as an example.

10mW ERP 10m WSPR tomorrow?

Starting tomorrow, I hope to start 10m WSPRing at 10mW ERP.  

Clearly, my previous attempts using 500uW work when conditions are very good, but 10mW ERP will be a good indication of how 10mW ERP (licence free under UK 8m ISM rules) 8m might behave.  An extra 13dB could make a real difference. If I get spots on 10m WSPR, I may not bother to renew my 8m TX permit as I will learn more experimenting for free with 8m 10mW ERP WSPR. I shall probably use 8M3ISM on 8m WSPR.

Judging by reports today, several spots might have been managed with 10mW ERP on 10m.