the May VHF-SHD-SHF subregional contest 2007 in OK2KKW
This contest was dedicated to testing and searching the new ways. The searching for new ways, new technical solutions, new bands and new operators. After the last year stolen affair of all our antennas hardware we have entire lack of time and money for members of our small club for restoration of all our stolen equipment (which we had been making out for several years) in short time period. And that's why we stand on the start with knowledge of this handicap. At least with some bands. First of all we made a decision envisage the 2m band as the contesting band. We hesitated to building this band at all, but in the end we decided to it because of it would be good idea for our new less experiences young operators, who almost never used to operate our station during the big contest which were dedicated to good result. This contest actually have started already at some time in Autumn 2006. After some unsuccessful tests to get ready truly functional, stable, reliable and repeatable PA for 23 cm with GI7b tube I gave it up and I had started looking for another solution. No that the GI7b would be an bad tube but I got know that this tube model 1943 is making amplification in effect due to positive reaction, which is making large temperature instability and non-linearity and the efficiency is due to long electron transit time very poor, which is strong opposite to requirement for stable and reliable PA. After longer effort I succeeded in repeatability of neutralization and I dramatically get better temperature stability of such a PA but as a result the gain decreased to few dB only, what was found unsuitable. So I decided to look on it in different kind of way and make something small solid-state in the short time period, however that work took me at last few more month of time. Nevertheless the result showed up at last, respective I thought it before the contest, hi. As the same long preparations as were in case of follow-up putting 23cm band into service (more, for this band we had to find new suitable parabolic dish which would be transportable for every contest to our contest qth because of possible new victim of metal pickers, hi) was made the objective for OK1BAF because of his development and manufacturing very new, sophisticated 3kV power supply for 2m PA because original high-voltage supply was stolen before the Field day contest 2006 as well. However Honza, 1BAF was overbusy so this objective same as the objective of Jirka to ensure new small trailer, wasn't realized in that time. The pleasure surprise in this list of unrealized objectives was announcement of our 2nd Jirka OK1ZAD (he is still bit external :) that he finished his new 13cm equipment and he want to test it in our contest qth. And because of it our contest participation increased to unusual number of 5 bands, we had to start solving the funny question where to place it. Luckily the weather forecast was favorable and the whole contest should be the quite island of the good weather among surrounding fronts, we choose the the extend (and not luckily as we discovered after it) variant, that all bands we'll be run from bunker and 2m band will be run from our house alone. The weather forecast became luckily true in opposite to the rest of OK and we were enjoying good and dry weather. Of course things got worse at last. As it's common the shame is coming in three steps. And that's why the announcement of OK1BAF (which appeared only few days before the contest) that he fail in preparation of the big 2m PA (because he got broken primary coil of PA transformer, which made all driving voltage and new transformer can't be wound from day-by-day) we had to put in our mind as the serious warning. We pay attention on it and it was paid for dearly with FT-1000 damage during the transport to our contest qth so the expensive transceiver become unusable. This was the second shame from the typical triplet. Because we hadn't second "2 ways exhaust" FT1000MP and we weren't able to use our transvertor with crystal filters, we decided to the contest participation on 2m just for fun with BAF's FT897 with small driver and small antenna. We hope that our QRM to our neighbors was minimal, hi. On 70cm we used new tube GS31b instead of old GI14b. On 23cm we used our second FT847, transvertor and two very new solid-state amplifiers. On 13cm we used Jirka's FT817 and transvertor on the mast with 10W PA. The 3cm band was based with good 27 years old FT290R and transvertor with 6W power out. The antennas you can see on the picture below. Immediately when the contest was started, the serious problem was occurred. The 70cm PA together with bigger installed power requirement from 23cm PA pull down voltage in our one phase network from 230 to some 140V (!). It was caused especially by new solid-state PA's with switch-mode power supplies and UPS placed before the 70cm PA, because this kind of power supplies have in contrast to till this time used linear supplies with transformer the attribute, that during the voltage decrease pick up bigger amperage from network so the voltage from the network decrease ones more and the power supply pick up bigger amperage etc... The practice knowledge of things of this avalanche effect take us to abortion of our 70cm and very soon we sent our messengers to Karlovy Vary to look for regulation autotransformer which would help us increase the voltage of our 400m long power line. Till that time we had been running the 70cm with the barefoot FT847 only without the PA. At about 20utc we successfully increase the voltage. But first there was made the small mistake, voltage increased to some 275V (!). Immediately the 10A fuse burn out because the solid-state PA have on the input varistors and for a such of the voltage they are representing short-circuit. But luckily all outlive. The input voltage in our house we adjusted to 245V and we're starting contesting again. If we don't drive the 70cm PA more then about 200W out, all is running ok even if the network voltage is fluctuating "a bit". You can see it if you click on the right picture (the middle of the gamut is 150V and right backstop is 250V). But let's back to the contest begging. We started and even better Matej, OK1TEH on 23cm is making plenty of good contacts. And It's fine, new PA's need to be run in. More you can read in his report: ................................................................................................................................................................................................................................................... I was looking forward to this contest very much because I run my last serious 23cm contest one a year ago and during the UHF Contest 2006 we used QRP which was 6W only and during this contest meanwhile I was focused to 3cm mainly, the 23cm was operated by the Jirka, OK1ZAD (for most of that time). One year back we used old PA with GI7b tube by OK1VMS with maximal output power about 120W with very small reliability because the tube liked the bang sound so oftenly. The used antenna was full 160cm aluminum dish and it was stolen by the "gypsies guys" before the Filed day contest 2006 too, so we had to look for the substitute one. At last we succeeded with with the new wire wifi dish with estimative gain 19dBd so even smaller then the old dish was. The advantage of this new antenna was the small weight and mainly the small surface due to usual strong mountain wind. I tested new solid-state PA during the 1st subregional contest in March together with feed by the DL4MEA. The main reason was the overheating test after long contest operation and new PA successfully come up to expectations. More I tested the PA to the overheating during my 1st 23cm EME qso with Al, K2UYH on JT65c. Another good news was the 2nd PA's "brother" so I had the serious reason to enjoy the next contest indeed :-)) We arranged the equipment pretty early before the contest start so we had the time to set up all the important funny thing like a CW keying from the PC, computer network, rectification of the antennas by the beacons etc. The first qso before the contest was made with the Zdenek, OK1DFC from OL4A club, who told me that he'll run the contest with the QRP power 300W because he hasn't the PA driver for his 800W QRO PA with TH tube. Then I made fast qso before the contest, some lunch and contest was ready to be started. 14:00 UTC We began the contest on our traditional frequency 1296.215 MHz, new amplifiers were running properly, what a enjoyment against the old GI7b PA. In the first hour I made standard qso with OK2KJT and nice SSB contact with S50C. I made in 1st hour 26 contacts, it wasn't bad at all. 15:00 In the second hour I logged in the ON4KST, where I managed sked with Franco, I4LCK/4 (the MP3 record is here). This qso was almost without any problems, I just asked for RST+NR again and 705km qso was finished :-) Next I made qso with guys from OM8A, they had the strongest 23cm signal from all OM stations, congrats. On the chat I saw, that there is good Rain Scatter in the OE area and Claudio is working dozens of long path qso's like with OK2M, DM7A, DL6NCI simply all stations around us ;-) So I
was running to the Jirka's OK1ZAD 13/3cm van more frequently, because it
was his first contest on 3cm, unfortunately this RS qso fast complete at
all. So at least we made contact with
Tom, OK2PWY.
This my "foot band changing" was lucky in one way, the
23cm PA's had time to get cold. 22:00
It's almost midnight of the
local time and good time for the some nice QSO to the
S5. I thin hour I worked
good qso's with S57C and Jože, S51ZO,
however it isn't 59+++ like usually. Really bad
condx to the East and East south. And really the 13cm contact was failed. 00:00 The GMT midnight coming unobtrusively and the 2nd round of the contest too. The wind outside the caravan is calming down and because I see the DXcluster full of the super DX contacts between the EA1 and OZ on 70cm I'm looking forward to the morning crown of Spanish stations from the Pyrenees :o))) Early morning I was
woke up by the Jarek to make a operators change. He told me that he almost
complete qso with F1PYR/P from JN18 which could be over 780km. When I
arrived to contest caravan I found the reason. In the second PA wasn't
running quiescent current. It can be say in the different words, the PA is
burn out, crashed.. Since now the contest is continuing with the one PA
and one dish. This PA is being often overheated is the output power
is about 80W. 73 and cu in the next conted under OK2KKW de Matěj, OK1TEH ................................................................................................................................................................................................................................................... So this was the contest view of Matej, OK1TEH. The night 23cm PA damage was painful and the final unlucky triplet. The problem that it stopped well taken off contest is one point of view. The second is worse that it's still unanswered question, what was the reason. To all appearance the wasn't any reason for it like a temperature or bad SWR, voltage or so.. And until we get know what was the reason of the solid-state PA failure, we have really serious problem which can be repeatedly caused again. But this contest isn't running on the 23cm only: on 432 MHz is contest continuing calmly and as a usually. We lost lot of points in the contest beginning due to problem with unsuitable voltage but after that the contest was continuing on the old way even with the small power. After all we finished with almost the same score like in the same contest one year later. The conditions to the South were poor, the DL activity was low but on the other hand it was enjoyable, that the OL7C didn't make any of QRM. The guys from DM7A was pretty strong but their frequency was around the .160 and because we have them in the most uninteresting direction to the north Poland, the QRM was quite OK. Worse it was with QRM from the Michal, OK1GHZ on the Klinovec. Not only spurious up to S9 but even more when he swithched to the transmitting, the noise pop up to S7 which was killing our RX mostly in the East direction (sri OK2 stations..). So we are apologizing to all calling stations from this direction without the effect. The 432 MHz result isn't so good after the several hours lost and the 200W power, even the km/qso average is very low the as usual but the operation made the good support for the 23cm band and we are with this worse result satisfied. We are satisfied even more with our 144 MHz presentation. Guys (OK1BAF, OK1JFR, OK1XNG) had good opportunity to enjoy the contest without any stress from from the hot operation for the best score so they were satisfied as well. On Sunday after lunch, when all were fed up with the two meters QRM we packed up the station. Even now we aren't decided if we should send our 2m log as the check-log only in case that it was the "just for fun" operation, hi. The 13 and 3 cm bands were operated by Jirka, OK1ZAD. He was providing his new 13cm equipment and for the first contest on this band it was working more then properly. Worse it was with the 3cm band, because Matej was sending to him plenty asks of the skeds via the VUSC contesting program and Jirka, who was operating 3cm for the 1st time ever was fed up. So we lost some good potential DX which could be made via the rainscatter to the I,S5 and 9A. And more we didn't completed the fine QSO with the PI4TUE on the 3cm even when we copied them very well. PI4TUE was booming very fine but he couldn't get our 6W QRP (he jas 25W TWT). Maybe we had to hear something on the air. But even the 3cm wasn't any drama. Jirka tested, that his new 2320 MHz is working during the whole contest and the frequency is very stable. He need make something with weaker RX but it should be easily done before the next contest. What is so interesting from this multi-band experiment is that if you want food results you can operate both bands from the same table. Make an complete qso on the SHF take lot of time or even more then 10 minutes and if you get another band sked from the lower band, the second station used to have small patience to waiting some time before the qso is completed and operator is ready for it. So now is clear the we'll need (if we have sufficient operators number) to separate this bands for the better results in the future and both of station have to be ready to use separate antenna rotator with the PS as well. But even now we aren't finishing the contest report with our number of contest bands. How it was agreed before, we had the visitors by guys from DM7A (DH1FM, DM1KL a DG3UH). For the talk, common beer and mainly for the testing of qth for the EHF. So they brought the equipment for the 47 and 76 GHz. So we had first and rare occasion to try the fascinating operation on such a small frequencies. Even with the few microwatts of power. The first problem was the antennas orientation so we used good old photo camera with the flash, which was the target for the 2nd station where to point the antenna. And the pointing on the sked via the FM handy on the 70cm. At last - both station were pointed in right direction, elevation, right frequency and it's ready - the outstandingly strong signal. So our boss, OK1DIX (on the picture on the right) has the opportunity to try the joy of our first qso under OK2KKW on the 47 GHz abroad. We worked Hartmut from the DM7A a only few minutes after it we we made easy contact with Pavel, OK1AIY/P. Both signals were S9+.
But the miracle time isn't finished yet. When it works
on 47Ghz, why not to try it on 76 GHz? The power is almost a half but the
antenna have more gain - and really, Vlada, OK1VPZ is starting the qso.
The antenna pointing is a bit more difficult but even on this band we
succeeded to find the signal of the DM7A and complete the contact too.
And stop talking about it, try
listen from the movie, how we were copying the
Hartmut's signal on the 4mm.
And for the disbeliveers you can see the video record of our small piece of that 76GHz contest contact between the OK2KKW and OK1AIY/p.
On the beginning I was writing, that this contest was dedicated to testing and searching. Thanks to Jirka and his 13cm we were put to the new situation - our usual WIFI connection link, which wre used for the computer network on between the 400m far contest place on the bunker and on the house weren't suitable any more. So we prepared our old cable modems, which know the "outstanding" speed 64kbps, but BAF is getting out new gadget - PLC modems! We're installing them to our long long power-line cable and what in hell - it's working! The connection quality is excellent and even if the fast the we have the autotransformer in the house and lot of switching-mode power supplies on the bunker. The connection speed is about 10Mnps. So don't be silly - PLC is ideal thing for the radioamateurs :-)) And on all bands, which we used during the contest no QRM at all. Lada OK1DIX who is the member of CAV organization is watching the PLC with some contempt first but at last he appreciate the unquestionable benefits. Thanks to the PLC we can enjoy the internet on the same PC with all VUSC4WIN opportunities. Online access to the rain scatter radars map, ON4KST chat and more applications on the each workstation which is beyond price. The internet interface was proceeded by the OK1XNG's router and it was shared in the network by the PLC. This stuff we have in the house because of 2m so there isn't any QRM for the local installation of CDMA. Yep and even one advantage is remarkable: we have cast-iron grill. Thanks Majka for a s such good stakes, really cool! The
contest is ending. Even last 70cm contact to the ON and it's the End.
Weather was fine, OK1TEH made on 23cm our the best result in our history
(although the smaller power), 2m was enjoying band and all guys were happy
to run the contest as the wanted to, OK1ZAD is smiling above the 13cm
equipment. Meanwhile others are leaving we're going to to Otta's pub. But
before it out final group photo. Is anything more to be said? Cya in the another next contest! 73! de: OK1TEH, OK1DIX, OK1VPZ, OK1DYX, OK1ZAD, OK1JFR, OK1RK, OK1KN, OK1XNG, OK1BAF and also from Pepa, who was smiling on our all work forbearingly
the
report was written byl OK1VPZ
together with OK1TEH Preliminary results:
*********************** 432 MHz ************************************
* Number of valid QSOs: 289 *
* *
* Best DX: JO01PU 819 km call: M1CRO/P *
* *
* Countries worked: *
* 71xOK 172xDL 5xPA 2xOE 3xON 4xI 5x9A 6xOM 4xS5 8xHG *
* 2xG 4xSP 1xLX 1xOZ 1xSM *
* *
* Total sum of points: cca 75000 *
********************************************************************
TOP 10 km ------------------- M1CRO/P JO01PU 819 G8P JO01QD 807 IQ1KW JN34NO 772 I4LCK/4 JN54PD 705 HA8V KN06HT 701 9A2SB JN95FJ 698 IZ4BEH JN54WL 662 I4YNO JN54KP 656 PA6NL JO21BX 630 9A5Y JN85PO 630
*********************** 1296 MHz *********************************** * Number of valid QSOs: 132 * * * * Best DX: JO02OB 827 km call: G3XDY * * * * Countries worked: * * 27xOK 69xDL 4xS5 4xI 4xOE 3xOM 1xSP 2xSM 9xPA 2xOZ * * 1xLX 2xG 1x9A 1xON 1xF * * * * Total sum of points: cca 38000 * ******************************************************************** TOP 10 km ------------------- G3XDY JO02OB 827 M1CRO/P JO01PU 819 F6DKW JN18CS 784 IQ1KW JN34NO 772 I4LCK/4 JN54PD 705 IZ4BEH JN54WL 662 PI4Z JO11WM 637 PA6NL JO21BX 630 PA0S JO21FW 606 SM7ECM JO65NQ 589
*********************** 2320 MHz ***********************************
* Number of valid QSOs: 27 *
* *
* Best DX: JN99AJ 393 km call: OK2KJT Average: 161 km/QSO *
* *
* Countries worked: *
* 15xDL 9xOK 3xOE *
* *
* Total sum of points: 4357 *
********************************************************************
TOP 10 km ------------------- OK2KJT JN99AJ 393 DL1SUN JO53PN 367 OE3A JN77XX 354 OK2BFF JO80HB 276 OK5Z JN89AK 257 *********************** 10368 MHz ********************************** * Number of valid QSOs: 21 * * * * Best DX: JN99FN 416 km call: OL7Q Average: 155 km/QSO * * * * Countries worked: * * 13xOK 7xDL 1xOE * * * * Total sum of points: 3263 * ******************************************************************** TOP 10 km ------------------- OL7Q JN99FN 416 OK2KJT JN99AJ 393 OK2PWY JO80HB 276 OK5Z JN89AK 257 DL1KC/P JN58QH 254 *********************** 47 GHz ************************************* * Number of valid QSOs: 2 * * * * Best DX: JO60LK 13 km call: DM7A Average: 12 km/QSO * * * * Countries worked: * * 1xDL 1xOK * * * * Total sum of points: 25 * ******************************************************************** *********************** 76 GHz ************************************* * Number of valid QSOs: 2 * * * * Best DX: JO60LK 13 km call: DM7A Average: 12 km/QSO * * * * Countries worked: * * 1xDL 1xOK * * * * Total sum of points: 25 * ******************************************************************** |