Hayden's Amateur Radio Blog - https://www.youtube.com/c/HamRadioDX?sub_confirmation=1

500km (310 miles) on the 2.4 GHz and 3.4 GHz Ham Radio bands!

Oct 242019

Last night, 22nd of October the Hepburn charts had a prediction of strong to very strong tropo ducting enhancement over Bass Strait. I promptly got in contact with Rod VK3BQJ and Geoff VK3KGR to attempt a contact from Mt.Wellington near Hobart.

Once I arrived after work (at approx 6pm) I could immediately hear the VK3RGI beacon on 2403.434 MHz, faint but there. Richard VK7ZBX joined me on site and we attempted a contact with Rod and Geoff. Neither could hear us and we even attempted digital to no avail. Convinced that the conditions were there and likely to improve as the sunset, we made a decision to try once more before packing up at 8pm.

Whilst we waited around for conditions to hopefully improve, we setup 3.4 GHz to monitor the VK3RGI beacon on 3398.434 MHz. With some tweaking and good ears we could at times hear the beacon in the speaker of the radio and could clearly see a trace on the waterfall.

Then around 7:30pm we got a call from Ralph VK3WRE who said he was intending to go portable to work us from Mt Tassie, 10km west of the 3RGI beacon site and higher. Richard and I decided to wait around and try a contact with Ralph who would take about 30 mins to get to his portable location. By this time the temperature was still 10 degrees, with an apparent temp of 1.4 degrees. Someone who shall remain nameless didn't think it through that wearing shorts would be a good idea! Whilst I put a jumper on, Ralph setup with Dean VK3NFI.

The beacon was exhibiting QSB fades over a few minutes, it would almost disappear then come back really strong. We attempted 2.4 GHz first and Ralph was a rock crushing signal 5/8. We exchanged details and decided to move to 3.4 GHz. We got the dish setup and roughly aligned (bearing in mind it is rather sharp). Well we didn't need Ralph to have the keyer on long, he was 5/8 again and arguably a better copy with no QSB. We didn't even have to peak the dish!!

We again exchanged details and decided to extend the national digital record on 3.4 GHz using FT8. I went to fire up the laptop - dead flat! We'd forgotten about it running all afternoon! I quickly said to Ralph I'd go and charge it up the road at the VK7RTC repeater site (lucky I had the keys). 15 minutes later of charge I returned. Ralph had been working several over VK3's on voice and digital.

Both Richard and I managed a FT8 contact with Ralph and the laptop promptly died 60 seconds after completing the contact!

This sets new records on 2.4 GHz for VK7 voice and 3.4 GHz digital nationally at just over 500km.

Thanks to all stations who made the time to participate.

Hayden VK7HH

BG7TBL GPSDO and 10 MHz Distribution Amplifier

Oct 092019

An affordable 10 MHz GPSDO module? The BG7TBL is a popular GPS disciplined oscillator available on eBay. Many ham radio operators use this as their 10 MHz reference for frequency locking radios. They come in two versions, one that is sine wave, the other a square wave so choose according to your application. A handy GPSDO kit for the shack!

I also review and show the operation of the matching BG7TBL GPS 10 MHz Amplified Distribution system.

Interesting 6 metre DX

Sep 222019

This morning I was randomly checking the 6 metre WSPR results for my station and I noticed the following:


Why is this interesting? Well let's show all the stations on a map.


Notice how the stations are evenly spread out. The red circles are estimated midpoints of the path. If this was Sporadic E (remember we are still only just into Spring here in VK) then there was potentially three clouds that had formed or, a really intense cloud somewhere over the north of Tasmania which was allowing 6 metre signals to be much shorter than normal. You'll notice the signals to VK3DXE and VK3II were in the + range at around 550km. Of note is that the above stations only received one spot from me at this time of 04:44 (2.45pm local).

Just another example of how WSPR finds potential openings that would otherwise remain undiscovered.

Sporadic E out of season - Spring 2019

Sep 162019

Over the past few weeks I have been running a WSPR transmitter, using 50W predominately beaming toward VK2. An interesting thing occurs on this path. 

These are the stations that have heard me:

VK2HC: Once (1081km)

VK2DVM: 3 times (1095km)

VK2ZMT: 22 times (1189km)

VK2XN: Once (1443km)

What is interesting about this, is that it is currently Spring and not in Sporadic E season. The approx midpoint of most of these paths is over the Australian Alps. It's not uncommon in summer to see stations on this path very very strong. In fact they are probably the strongest 6 metre stations during E events. But what about these events out of season? Are they random Sporadic E clouds forming? From the data that I have, I can ascertain that spots were received by the VK2 over at least three separate days, and I recall at least two days in a row where VK2ZMT was hearing me.

I recently come across this video on YouTube from the RSGB: https://youtu.be/wn5as91ndG4


Watch the whole video but if you skip to 9:12 the speaker talks about "mountain waves" which may be a contributing factor to Sporadic E. An interesting theory and thought.




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