So the final installment of all this activation activity was The Great Sandy. We were camped on Lake Cootharabra and I used this as my base camp for the activation’s of Tuchekoi, Tewantin and Woondum. I did not put a full activation of this park on as I have done it a number of times already. But rather just chased the other activators for park to park contacts.
We had this pair of ducks decide that our campsite was going to be their campsite for the whole weekend. They slept under the table, chased away any other birds and pretty much took ownership of everything. Pretty funny.
Woondum is also another new park. It is also a SOTA peak and i did a dual activation for both programs. I am not much of a SOTA person, this was my first SOTA activation ever. SOTA in vk4 is a lot of work for little reward, most peaks are low value, this one was 1 point, and most require a lot of effort to climb to the summit.
Anyway, this summit was also a drive up and a short walk. I made 56 contacts from VK1,2,3,4,5,7,8 and ZL. As well as park to park contacts with VK4AAC and VK3ANL. It was also nice to have Sid and Adelle ZS5AYC and ZS5APT call in, who are both back in VK4 again visiting with family. Both are very keen on SOTA and will be out and about doing activation in the not to distant future.
Activating Position APPROX -26.262834, 152.813716 using google maps, need to use SOTAMAPS to get the exact summit co-ords.
Sometimes when laying out a board you have to create your own footprints. Out comes the digital calipers and you start making measurements, but, what if you make a mistake, the board becomes a waste of time. So, i like to print out the board layout at 1:1 resolution and then overlay my parts and where possible push the pins through the page to check everything lines up right. Saves in the long run 🙂
On thing i manage to do well, is make a mess. Not so great on the cleaning up or being tidy and organized. But i got a little excited the other day and started to sort out all my stuff and make it into some sort of organized mess, where i can at least find things.
Starting with my component trays, I have them all stacked together now in the one location, the only thing i need to do is to add front lables so i know what is in each tray. Each tray has its own theme so its just a one word label that is needed, resistors, transistors, IC’s, Arduino etc.
So after getting all my componentry away and tidy, i had some bench space left over, and do i cleaned up and organized my work and test area of my bench. Things are nice and clean for now, I just need to find a place for my current project, the 3 boxes on the upper shelf and fill that gap with something nice like a spectrum analyser. HIHI.
So we got some nice winter sun today and I was able to test them out in typical sun conditions and we are making pretty much close to the theoretical maximum they can make, peaking at 550mah and averaging about 440, all in all this is rather good and well suited to the purpose i have in mind for them, keeping a portable rig running longer on a 7ah deepcycle.
So today i thought i might be fun to whack together a VXO for 80m and see just where i landed me. Now i know that pulling crystals very far is not an easy thing to actually do, especially when they are on the lower end of the spectrum. So with this in mind, i set my initial goal as 1khz pull. I figure if i can get that, its kind of usable in other projects.
First job is to get on google and find a simple schematic, with that out of the way, I can get to putting the ugly back into ugly style home brewing and slap something together on some scrap board.
And slapping together is just what I did, a pair of 3.6864 xtals, with 10uH series inductance and 170pF of capacitance in the polyvaricon.
Give it some power and connect up the scope and freq counter and am greeted with this ugly waveform, harmonics, bias, its a mix of everything that is wrong in the world. So let see how far we can pull these bad boys.
High freq is 3.6867
Low freq is 3.6863 HAHA we managed a whole 400hz agility, as good as useless, but it was rock stable, pun intended. So i did a but of goggle foo and found that I can get much better pulling power with more inductance, 10uH is orders of magnitude not enough, so i added another 200uH in series and got a total pulling power of 2khz. 2khz is not much in the scheme of things, but, for a cw 80m rig, 2khz is a nice slice of spectrum to be frequency agile on.
So, whats next? rip out the xtals and drop in a ceramic resonator and adjust the series inductance to suit. Should see a good pull range with that.
I got to thinking the other day, as I was pondering placing an order for a couple more books from Pages of Cobram that i have started to amass a bit of a library and I probably should write a bit of a review of them. Oh and if you are looking for a bookstore that is not going to mess you about and is competitively priced, give Peter as pages of Cobram a call and place your order there. Just about all my books have been purchased there and never had an issue, ever. I found a book that was not listed and they even ordered it in for me, a 1 off, cannot complain about that.
Anyway, on to the books:
Homebrew Cookbook and Building a Transceiver by Eamon Skelton: Skelton is a good writer and these books are and interesting read, however, cookbook contains a lot of the same material covered in transceiver. If i was buying all over again, i would pick one, either one and be done with it. I am not sure how useful transceiver is in actually being able to build a transceiver from whoa to go, but it is a good read that documents many of the decision making processes the home builder faces. A worthy read, with limited scope for developing the documented project. 6/10
Experimental Methods in RF Design by Hayward et al: This is a book I love to hate, now dont get me wrong, this book is a tomb and a beast, jam packed with masses of information and probably the best text book we have on all things RF and Amateur Radio. Its just that it is hard to find the information you need, the flow is somewhat haphazard and illogical and it just tries to be all things to all men and does not really do any of them well. In some places its practical, in others massively theoretical. I think for me, I am always wanting the pertinent information and less of the fluff. Often times, bits of a schematic are just missing, like the number of turns on a bifilar winding, with a note to look in the transformer section, which is then masses of theory and I still do not understand why or how the turns ratio is calculated, other than most times in HF rigs, its 8T bifilar. Love it or hate it, or as i do, have a love hate relationship with it, its the best we have, but could be so much better and designed much more towards the practical person, rather than theory. 7.5/10
Hands on Radio Experiments by Ward Silver: These books are copies of what was written in the Hands On column in the ARRL mag. The writing is great the projects great, its just its not a complete copy of the column and they are not in chronological order. Its a little frustrating when a project references a project not in the books, or if it is, you need to search all over to find it. I find myself reading bits and pieces of these books over and over, generally before bed. 7/10.
Circuit Overload and RF Design Basics by John Fielding. Circuit overload is great lavatory reading, a useful schematic followed by an explanation of how and why it works. I have learned a fair bit from this book, all while sitting on the toilet. The sections on filters are almost identical in both books, and of all the books i have, these make the best explanation on how to design LC filters of anything i have read and for that info alone, make these books useful. 6.5/10
Radio Projects for the Amateur 1,2,3,4 by Drew Diamond: I find these books to be inspirational, while i am not all that interested in anyone project to build in its own right, when i am stuck for an idea, or a solution, these books seems to have it. The books themselves are copies of articles Drew has written for other publications, the explanations and descriptions are good, and generally give you all the information you really need to know without too much fluff. I will often pick one of these books at random and read an article or 2 before i go to sleep. 8/10
I have a couple more books i will add to this list later, and I have some new ones coming soon that I will also add to this list. Happy home brewing.