Monday 29 October 2018

First part done

The first ARRL weekend is over.
It started with heavy rain Friday afternoon but it cleared up Saturday afternoon and the remaining of the weekend was fairly OK besides some snow Sunday.
Managed in total of 39 QSO's with some new stations and some worked before.
Think the activity was higher this year compared to last year and Sunday evening activity was very good with a lot of stations QRV.

I believe the smallest station worked was K1DS with single yagi and 100W or so.
One funny thing was Tobbe SM7EOI who lives 35 km away uses 4 * 11 el DG7YBN antennas hrd good but we missed to work before my noise became to high at MS when I beam into my house.
We can only work when doppler is high as the tropo signal is so strong.

Did make a switch box for the pol switching Saturday afternoon but it did not work on the RX side and the moon was on its way up so I left it with fixed RX H.
Did work XE2AT with TX vertical and RX horizontal and tried to call CQ a few times V but got no reply's.
Later on Sunday afternoon I found that the cable I used from the relay switching the two RX cables in the shack was short circuit so after replacing that it worked as planned.
The preamp for the V antennas had lower gain so the noise level dropped but it worked well.
Worked JE1TNL using both TX and RX vertical so the system works.
Compared a lot with HB9Q RX on livecq when I changed the TX pol and all times it shifted 90 degrees and a bit lower level on V as expected.

Worked Bernie ZS4TX who has the exact same array as I do and when he TX V he was like -10 with me and when TX H he dropped to -27 so a huge difference.
Listen a lot on Bernd DL7APV with different pols and at some point he was more or less gone when I RX V.

Experienced some noise from time to time and did walk through the house with my 817 with a rubber duck on but did not find any source of extra noise but need to continue the investigation as I believe I have something interfering.
Some times I can detect noise with patterns in Map65 both in freq and time domain.

Sunday evening I had problem with MAP65 hanging when trying the decode so I could only at few times report to livecq.
Do not know why and I have never experienced anything similar before but Sunday night it was constantly hanging.
Besides from that and some high VSWR when antenna soaked the station worked without any problems.
Need to find some good settings for CW until the next leg as I tried a few times but CW does not sounds pleasant with my settings at the moment so I did not work any.

Saturday 27 October 2018

ARRL first night

So finally I got it all together in some way to be able to work.
Finalized the antenna yesterday and the rain started the same time and has not stopped since.
Had some other work to do yesterday so late afternoon I started the station up or thats what I thought.

















For some strange reason had I lost the nw Connection to the computer which worked the week before.
Tried to reconnect both ends on the cable but it did not help so I set up a WIFI nw instead.

Connected the rig together and got noice when switching on the preamp and the local beacon was fine but to amp did not TX when PTT was actuated.
Started bu testing the RIG but it was working as usual so the error was in the PA intself.
The investigation gave a broken PTT transistor in the PQL controller and fortunately I had an unassembled one so I could Exchange it.
Why it broke is a mystery but the only way I believe was the thunder hit we had a while ago.
















The antenna matching was terrible and for both pol only about -15 dB return loss.
Did not bother to build the switching logic for the dual pol so I will do that today.
The idea now is to just be able to switch between the two pols for RX and TX separately and one RX pol at the time.

Did manage to work 10 stations this morning with 300W output power and the propagation seems to be OK and hrd a lot but had some problems with getting both MAP65 and WSJT to work as I want them too.
Had a 3dB increase in noice when connecting the FCD to 28MHz RX line so from time to time I did not use it.
Experienced some increased noice and I need to look into that later today and when beaming toward west I beam in the direction of the house and the noice was increasing quite a lot.
Had some strong strange burst noice from time to time that I never seen before but it later dissapered so I will not bother at this time.

Weather forecast is some rain and windy and at the moment its snowing but hopefully it will not be so much as the past night.
Shall be QRV tonight and hopefully the propagation is good.

Tuesday 23 October 2018

Slowly getting there.

Slowly everything is coming together but still not sure I will be able to complete before Saturday morning.
The weather forecast for Friday evening and Saturday morning is snow and heavy winds so the weather might stop all activities but I keep on working.
One problem is that it gets dark just 2 hours after I get home from work so the time working in daylight is limited.

Weather proofing of the balun, relay and preamp for the horizontal antennas is a task and I was convinced I had a decent box for it but can't find it anywhere so I just bolted everything onto a piece of 2 mm alu sheet and covered it with a plastic storage box.
Have ordered a couple of new boxes but they will arrive next week.

Have made all cables and the H/V relay and V preamp box done so everything just needs to be connected together and the two RX cables drawn into the shack.

Got my high power permit a few day ago so now I am allowed to use 1kW output power again.
But I have only about 700W or so from the PQL amp and had no time to complete the Italab amp yet but it will be OK with that.

One funny thing is that there has been nearly 4500 readers to this blog and only one comment.
A few times I have consciously wrote something that was not fully correct but still no comments.

Planned to have the Friday off work to sort out the last pieces but forecast is rain the whole day so maybe that is not such a good idea after all.

Saturday 20 October 2018

8 Antennas feeding done.

Today I was able to finalize the feeding structure of the horizontal array.
The results was quite good after some tuning with moving the teflon pieces to acheive the best match.
Will try to move them more equal and for a good support tomorrow.
I struggled a bit finding a good solution to attach the balun in a good way so it took some time to complete and to assemble everything completely alone cause some extra moment to prevent anything brake or bend.
































Next is to build the new relay box and to make some new cables for dual pol RX and also for the horisontal preamp that will be positioned closes to the balun possible and I need a TX cable into the relay box too.

Did some supports for the open wires to and hopefully it is enaugh but I need to make a second support for the balun and relay and cables as only one is propably not enaugh.

















Needed to bend it or it would hit the mast when elevating and I need to have 70 degree elevation for to gain access to the the feeding.
Hopefully I will have the time to finalize everything for the first ARRL weekend but I have some other work to do also.

Sunday 14 October 2018

4 antennas feeding done

Today I managed to test the feeding I want to use for a 4 bay array.
As my stacking distance in horisontal plane is not an multiplier of a 1/4 lambda i made the vertical feeding wires slightly longer and bent them toward eachother slightly.


















The matching was some -25dB return loss but I did not try to tune it further but discovered that the vertical lines was slightly to long so I need to shorten them to fit perfectly.
Will continue making the other 4 dipoles and wires for thoose and also make the wires to connect the 2, 4 bays together.
Need to make some support for the balun and cables as the feedpoint will be at some distance from the main horisontal support boom.































The wires are interconnected with M4 screws and toothed washers and it seems ok but its a test but after looking at DL7APV solution using 4mm copper wires and soldered interconnections it looks as a much better solution.
Will ask the local electrical motor repair shop if they can get hold of 4mm copper wires to make a test later on.

Tuesday 9 October 2018

New dipoles

Last weekend I adjusted the elevation axis rotor and I can stand and reach the horizontal antenna dipoles very easy from the ground.
During the process I accidentally got stuck in a support wire for a HF vertical while rotating in azimut bending one antenna slightly but it was easy to bend it back again.





















Earlier test dipole I used 4.76mm copper tubing but have now tuned the antenna and bending fixture to 6mm tubing and it seems to work fine.
Tested to mount one dipole with through hole screws and nuts but discovered that the on the backside where the open wire line later goes the extruding bolt and nut was very close to where the feedline later goes.
I need to use inserted rivet nuts on the boom to avoid extruding anything in that direction but I have not been able to test that yet as the wind has increased and I do not want to elevate fully in high winds.



































The time is running out for the first part of ARRL contest so I need to step it up  and make the feedlines any day soon.
I have made the feedline distances yesterday and will try to stack 2 antennas together and measure the matching and if everything is as expected continue with 4 this week.
Decided to go for 200 Ohms feedlines and with 6mm wires the cc is 16mm.

Need to make some support for the feedlines when I drill and thread then in the lathe to avoid bending or braking them while the lathe rotates.
My idea is to use massive 6mm aluminium for the feedline and drill and thread in the end of each piece and then drill through the junction piece and with toothed washer just bolt everything together.
Will try to weather protect each junction with isolating spray.

Tuesday 2 October 2018

Antennas up again :)

Today I lifted the stack up again.
Managed it just before it started to rain so I need some time to level everything and adjust the readings of the indicators.
A Quick test showed a 2 degree offset on elevation and 5 on azimut.
Also tested to elevate maximum and I got Close to 70 degrees and thats enaugh to access the dipoles on the horizontal antennas from the ground.





















Weather proofed all connectors and matching close to the ground was fairly OK but could not measure after the lift as it started to rain quite a lot so that needs to wait to a better day.
Picture below is before weatherproofing connectors.

















Will continue with folded dipoles and open wire feedings and the new switch n´box.