Category Archives: Propagation

80M DX on the uBITX

This is a recording of W1MBB on 3.798Mhz at 0754 this morning. My antenna is a long wire strung between two trees with a homemade tuner. I also heard a ZL this morning.

 

So, what does this prove? That the uBITX receiver works well although I must add the AGC board! That there is DX out there if you know where to look. That amateur radio need not cost a lot. And, most of all, there is nothing to beat the kick of building a radio and using it on the air.

I know I could never work him on the uBITX but I also know that using higher bands it is perfectly possible to work across the pond on 2W of CW.

Contest time again

Having and SDR receiver makes it very easy to look at band activity. Today is the start of the two days of mayhem that is called the CQ WW Contest. What is interesting is the number of stations on the air when the bands are supposed to be dead!

A quick look at 20m at 1104 UTC showed wall to wall phone stations. The antenna is still a mismatched long wire so I guess I was missing the weaker signals.

There were a few stations on 17m but more on 15m. That was surprising and a quick listen found that they were all in eastern Europe and Russia. Good steady sigs with no QSB.

What interests me most is that the bands were not ‘dead’, there were people using them. There may not be the exotic DX out there but even that is still possible at times.

So, the only time we speak to each other now is to scream CQ CONTEST followed by 59 QSL. I bet that could be automated with voice talkers and some nifty software, if it has not been done already.

Update 29/10/2018 I dropped in on a mate working /P from the top of a local hill during the contest. He had modest antennas, a doublet and a 20m vertical both quite low. True he had a bit of power but barely 400W PEP. He had worked all over the world including VP8 on Sunday morning. His comments were the same as mine – who says the bands are dead! Don’t wait for a contest get on the air!

 

 

160m – Topband – best for solar mimimum

I was digging around on the net today looking for simple deigns for Topband,  160M gear.  I found this article saying that it was best for solar minimum:  “The 160-Meter Band: An Enigma Shrouded in Mystery” which first published in CQ magazine in 1998. Here is some of what it says:

“Topband is one of the last frontiers for radio propagation enthusiasts.”

“The correlation between sunspot numbers and signal strength is only about 5% as strong as the correlation on higher frequencies.

”There are several important components that can improve your chances of successfully working DX on Topband. […] The trick here is to wait for sustained intervals of quiet conditions over the high latitude regions.”

It used to be the band for local rag chewing and I get the feeling it is either classed as just that or seen as the preserve of DX chasers with huge antennas farms. It can be both, but we can all have fun on Topband over the coming years without the constant depression of low or non-existent sunspots. I have a 38m long inverted L and had reasonable results on 160M a few years back so please do not dismiss the band without giving it a try.

It also appeals to me because it was my first intro to amateur radio. I used to look out of my bedroom window across the road to an aerial pole in the back garden of the next street. It belonged to G3LIO, Jim Gibbs. He was the first licensed amateur that I knew, and he and his father were very generous in helping me to start short wave listening back in the mid-1960s.

I have a few projects to complete to get back on the air but over the coming months I will make some Topband gear and give it a try. It will be low(ish) power AM to begin with. I also like the idea of working /P with long wire antennas supported by tall trees. It is time to modify the catapult launcher!

The antenna

The antenna is back up after 6 years! Nothing fancy just an inverted L at about 11m (~35ft) and around 38M (125ft) long. Still need to put in a counterpoise in the lawn but the ground is rock hard after weeks of drought, so it will have to wait.

Also need a remote tuner and plan on making one based on an Arduino.
https://hamprojects.wordpress.com/2016/12/31/hf-automatic-tuner/

I have a nice waterproof box that housed a commercial tuner to house it and will probably make it solar powered to avoid have to DC up the coax. Hope to get the coax in this week, it is something like a 40M run of RG-213. So, work to do before winter!

QRP does work!

Time and time again I see the trite remark that life is too short for QRP. Well, QROers you can do amazing things with very small amounts of power! Oleg Borodin, RX3G and Leonid Bovin, R1LB have completed a QSO on 14.060 over a distance of 970kms with each using 80mw. Congratulations to you both for keeping real amateur radio alive.

Life is too short NOT to try QRP!