Short update

Nothing exciting happens at the moment.
Working with preamp designs and is waiting for one batch of PCB's from the Chinese vendor but it will most likely take another week to arrive.
Tried to match the YU1AW design better but failed and is rethinking the design a bit.
Already working on a second design with two transistors in series to achieve more gain and to reduce the number of preamps to only one.
That is not completed yet and I wait until the first set of boards arrive so I can debug the first stage and optimize input circuit before ordering the second version.

Got the 4*40 displays I ordered for the VK5DJ controller and they worked very well but I missed the part in his design that he stopped including the SW clock module so I needed to order a HW clock module to finalize it and it has not arrived yet.

Besides from that I wait for the dec of the moon to increase and the V31 expedition to start.
Helping my sister renovating her new house as well so I am keeping myself occupied.

Vertical polarisation

Tried to work the DX7EME expedition in the beginning of the week but did not receive anything at all. Not even the slightest trace of them.
They TX circular polarisation but later discovered an error on one dipole which led to some sort of linear pol and the few stations receiving them that could alter their polarisation saw that they where stronger on vert pol.
So how to add vertical polarisations on the setup I have.
Try to rotate the entire stack is not doable and to setup an entire new vertical seems to much work.
The two possible sollutions I see is to add an array of vertical antennas on the booms I have today but in front of the vertical antenna mounting tubes or go large dish.
I did some calculations and a YBN 14 element yagi would fit in the front part of the present antennas.
The stacking distance will be larger the optimum creating sideloobes stronger but in my mind the easiest solution to the problem.
Would not interfere with the horisontal array even when I change to open wire feed as the stacking cables would be coaxial for the vertical array and "hidden" on the mechanical structure of the antennas.
I have allready decided I will rework the setup next summer with lowering the mast and adding open wire feeds instead of the present coaxial and I will also remake the plate where the triangular horisontal boom is assembled on as it seems as the weakest part at high winds.
This will require the array to be taken apart anywhay so why not in the process drill for vertical element too.

I was intended to try to optimize the amplifier tuning but did not find the time to do it this week but hopefully will find the time next week.
Had a nice chat with Toshi, JE2UFF the other day on the HB9Q chat and found and started reading his blog and they are designing a kW amplifier that looks really interresting.

Have had a problem with the preamp not starting when switching to RX and investigated that and it turned out that the Relcom RX / TX relay up in the array was occationally not making proper contact.
So I removed it and pulled it apart to clean it but discovered that the TX part was quite severely burned and RX part oxidated.
Bought this relay and the other I burned completely just before the 1st part of ARRL contest in october used from a ham in Sweden and starting to suspect that they was more or less burned allready when I got them.
Have never exceeeded the max power rating and the have seen very moderate use here so most likely something has happned in their past life.
Cleaned it up and it works ok at the moment but need to change before it brakes completely.
Have some Russian REW-14 that will handle the power but then I need to add an isolating relay for the preamp as they have less isolation then the Relcom I use now.
Have a box of old Sievers Labs relays too which are similar as the Relcom and has some 80dB of isolation on 432 MHz that could be used but I have no information of power handling capbillity so It could be a gamble to try.

Septum

Have plannes to also test and work on 23 cm with a 1.9m dish I have.

Its a deep one with f/d at 0.3 so a septum without choke or other beamforming seems correct and after discussions with Ronny SM7FWZ the work started.

Completed it fairly quickly but final tumimg will be done when positioned in the dish.

Did not fully acheive the data read about but some 25 dB in return loss and isolation seems acceptable.

Ordered some SAV541+ Hemt transistor which arrived last week and I put them into a yu1aw preamp and the results looks promising.

It is not 100% stable and poor input match but still lower Nf and will be worked with some more.

It might end up in another design as the input filter was not as sharp as I want it.

Any suggestions are wellcome.

Made some rework of the amplifier as well and one thing I noted when very carefully checked the assembly was the small coaxial stubs used as capacitors was mounted 2mm away from the instruction so I changed that and redraw the 50V DC supply part completely and checked the lowpass filter.
Nothing found in the LP filter and when assembled back together again the results was even worse than before.
30A current gave some 300W out so completely off.
Did change the positions of the coaxial stubs again in the other direction and that seems to be the way to go as 30A now was 600W and thats how I worked it during the weekend now.
Blew a new decoupling cap too so did a second rebuild of that and then it was stable.
Will continue optimizing placement of stub cap for further improvement but not right now.

Did work the second part of ARRL too and the D44 DXpedition fairly easy but have caught a severe cold and is constantly coffing and has slept in total maybe 10 hours since thursday.so a bit tired at this point.