15 Jul 2021

Walk earlier - NOT amateur radio

 

As it was supposed to be hot today, we did an early walk. It is now cloudy! This butterfly obliged by sitting still as we took its photo. Most fly away just at the moment the shutter is about to close!  😞

10m WSPR TX 500mW (Thursday)

Since breakfast I have been on 10m WSPR TX. So far (at 0950z) I have been spotted by 14 different stations.

UPDATE 1249z: 17 stations have spotted me today.

6m FT8 RX with the V2000 vertical omni (Thursday)

Since breakfast, I have been on 6m FT8 RX with the V2000 omni vertical. 61 stations spotted with the furthermost 9K2YM (4714km) in Kuwait.

UPDATE 1038z:  66 stations spotted on 6m FT8 RX so far today.

UPDATE 1246z:  92 stations spotted.

UPDATE 1853z:   103 stations spotted. Season ending?

WSPR idea

 Jay, W5OLF, has asked me to forward this:

"At the end of last year I designed the Retro-WSPR exciter around an Adafruit Trinket microcontroller and a 74HC4060 counter chip (see photos below).  Retro- I guess because it is at a single frequency and you rely on up/down conversion to get it to the WSPR band you wish.  It uses only one chip besides the microcontroller that is a 4.194304MHz oscillator and buffer, which is the RF out square-wave, and a counter that counts down to a 256Hz clock.  The 256Hz clock is input to an I/O pin ‘software interrupt’ of a very simple Python program on the Trinket.  This provides WSPR symbol timing and 2min timing by counting the beats of this clock.  I have never heard anyone proposing such a design in that the WSPR symbol time interval is 8192/12000; if we divide numerator and denominator by 32 we get 256/375.  Thus if we count 375 beats of a 256Hz clock it is one WSPR symbol time interval.  The next trick is that the clock at 4.194304MHz also is modulated with its mean frequency preserved - for long-term good timing - with the WSPR symbols by slightly changing the VCC to the counter chip (it takes very little voltage change to increase the frequency by 5Hz) using the A/D converter pin from the microcontroller.  This setup puts out a 0Hz drift WSPR signal with average low delta-t drift for months once the oscillator is adjusted to the correct parameters and the crystal ‘aged’; although, it is only the exciter. 

Now the next question is the up/down conversion circuitry which I have not experimented with personally but would use standard gilbert cell IC and transistor amplifiers and bandpass filtering.  If any of your readers of your blog want to experiment with doing this I can provide a unit or PCB and crystal for shipping postage only as well as emailing the software to them.  The I2C interface is brought out from the Trinket micro and can easily be used to initialize a SI5351 board to an up/down conversion frequency to feed into the mixer.  Please feel free to post this email on your blog.

73’s, Jay, W5OLF"



Antennas mended

Thanks to the efforts of Richard G3TFX, my antennas have been mended.

I now have my V2000 and endfed halfwave for 10m re-erected at full height again with new coax cables. In the past I could have managed to do this, but I feel so giddy that ladder work is all but impossible.  

Richard has worked tirelessly in the true spirit of amateur radio.

Oscar 100 activity

 

Every few weeks I try to give an update on activity levels on the narrowband transponder on Oscar 100 using the on-line SDR at Goonhilly Down. 

The most recent peek was last evening in Europe. Activity levels were moderate, certainly not busy. 

Sunspots - Thursday July 15th 2021

 Solar flux is 72 and the SSN 23.  A=14 and K=2. 

14 Jul 2021

Pass it on - NOT amateur radio

“Pass the parcel. That's sometimes all you can do. Take it, feel it, and pass it on. Not for me, not for you, but for someone, somewhere, one day. Pass it on, boys. That's the game I want you to learn. Pass it on.” 

This famous "pass it on" quote from "The History Boys" by Alan Bennett resonated with me. 

In the end this is what all of us has to do. We pass on our experiences of life to children, friends and colleagues. Not one of us is perfect, but we must strive to pass on what makes the world better to those around us.

Bellbind - NOT amateur radio

At this time of year, bellbind flowers look great. 
 
Sadly this plant can strangle garden plants. 

It is also known as bindweed.

ICOM IC-705

This QRP radio has been on sale now for several months and is proving very popular. It has its own battery pack (5W) or can run off an external PSU (10W).  

Although I have had mine for several months now, I have only scratched the surface of what it can do.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/commercial-rigs/icom-ic-705 .