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Poruke - 9a6c

 Str: [1] 2 3 ... 92
1
Alpe adria UHF/SHF / ALPE ADRIA UHF 2021
«  : 16. Lipanj. 2021, 11:31:07 »
I tako, još malo pa nedjelja…

Ovaj put bez mene unatoč prethodnoj najavi.


GG

2
9A microwave contest / Odg: 9A microwave 2021
«  : 13. Lipanj. 2021, 17:12:39 »
Malo smo off topic, ali rekao bih da je problem sve vremenski pa možda i nismo😔

3
UKV tehnika / Odg: SERVICE MANUAL
«  : 11. Lipanj. 2021, 20:14:19 »
Priupitaj 9a2bw na mail, ima da u klubu.


GG

4
9A microwave contest / Odg: 9A microwave 2021
«  : 11. Lipanj. 2021, 15:04:19 »
Momci, javio se Matej Ok1TEH koji prati ovu našu raspravu oko mikrovalova i poslao malo duži mail s molbom da ga ovdje objavim, a mislim da ga vrijedi pročitati. Na engleskom je, ali uz malu pomoć Dr Googla mislim da će biti zanimljivo ;)

***********************************************************************************


Hi guys,
I'd like to write out few findings related to problem with 23cm QRM
from commercial or military towers and how to remove it. First you
must find out if the signal is in band or not by some spectral analyzer.



1) QRM by inband commercial signal
If the signal make problem in band, there is usually very little
what you can do.. One partial solution is to build up narrow dish
with high front to back suppression and use LNA with high IP3..



2) QRM by outband signal
If the QRM is caused by signal out of band, it's very important to
find out, how far (MHz) is the unwanted signal. At my home QTH in Prague
I had problem by DVBT2 tower operational some 300m far with few kW.
It was running DVBT some 300MHz below 1296 MHz so in this
case it was relatively easy to buy or make low ATT filter.


Making such a filter is relatively easy, we made such a filter
to suppress the mirror for the 28/1296 MHz transverter check out:
http://www.ok2kkw.com/00000104/preselector/bpf_23cm.htm
I asked to Beert, PE1RKI, because he has very well done boxes and machinery
and at least it saved lot of time. In the case it was easy because the
source of QRM was several hundreds MHz away so the
cross attenuation was only of 0,2dB.



Much worse situation happed at our contest QTH JO60JJ,
as we suffer from radar from from 14,4km far Auersberg radar
which is operating around 1259 MHz with 2,5 MW in pulse.
As the result I asked to RKI to prepare special narrow BPF version
however due to very narrow bandwidth and very high suppression
it has relatively higher cross attenuation. It's because of problem
with Q at this high frequency. Luckily we found out that such a filter
at our case was working well even when it was placed between
LNA and transverter, so the higher attenuation was still acceptable
because the whole noise figure wasn't  corrupted so much
(we use separated RX/TX path).



By the way if you have such a problem at 2m with FM BC,

check out https://www.antennas-amplifiers.com/144mhz-bandpass-filter-bpf

it's great BPF and I use it with good success..



3) QRM by usage of bad kind of LNA for contesting
For city environment with strong outband signal it's better to use
LNAs with very high IP3 like MMIC PGA103+ or some alternative.
Don't use 2 stage LNAs like VLNA from G4DDK or old LNA
with MGF1302, they are fine for EME, but not for city environment.

I had bad experience with LNAs from SSB electronics, little bit better
are HEMTs (Kuhne), better is PGA103+ but currently the best is probably LNA
from US4ICI with SKY67151, compared to PGA103 it has much lower NF
https://vhfdesign.com/lnas/lna-eme-sky67151-for-23cm-and-21cm-bands.html
Remember for 23cm tropo contests that you really don't have to use 0,1dB NF LNA,
anything below cca 0,8dB is ok (because of high thermal noise from background)



4) Operation at on4kst chat
I read your discussion, It's not easy task.



At 23cm I used to ask to more people, because I use 2 or 3 (since June)

independent antennas, so I can turn them to more stations at the same time.

Sometime it's problematic that you ask somebody for chat and you are called

at random by some other local station, so sked partner has to wait and with

nowaday smaller patience he became to be angry, that he must wait for you...



I always try to do my best and ask stations only if I checked at Airscout
that airplane is already coming. But guys please release that the situation
in Middle Europe is far different to some DX area like 9A. We oftenly work
30 stations on 23cm during first 1 hour of contest so the pileup is big
however when you wait and ask some 9A station later like around 19utc
when you have more time for skeds, at the meantime he often go QRT
or try some other band.. An another thing is QRM situation, I often ask
the sked partner to move let's say to  .310 or higher.
During some contests it's very problematic to find any free frequency
for CQ between 1296.150 to 1296.290 MHz...



In any case if you are fed-up with the too fast chat traffic, try use our VUSC

contest log because it has it's own KST chat client with very good

user text filters. If you are QRV 23cm, please write it at your name in

chat and if you are just listening, please select in KST chat that you are

"off the chat" so then is station marked with () and almost nobody will bother you.



At the end I must say that S5, 9A and YU operators are very well skilled
in CW/SSB operation so it's big pleasure to work you. And yes of course

please always send full rst+nr + loc code, the situation when
somebody send rst+nr only I don't like either hi. Last words: if you are small

stations with 10W, please realize that Airplanes are great help so even with

your small setup if you know CW, it has sense to try QSO up to 500 km,

just give it a try and please be patience hi.



73
Matej, OK1TEH

********************

Najbolje od svega mi je što je teško naći slobodnu frekvenciju  i da postoji pile up na 23 cm, e da mi je to doživit...

Naprid naši!

73 GG

5
9A microwave contest / Odg: 9A microwave 2021
«  : 10. Lipanj. 2021, 15:29:10 »
E kad mi vrag ne da mira...

Vidićemo kako će bit u AA... Povrh kuće su crkva i groblje i normalno da nema šuma😋

Grobna tišina na 151 m asl...

GG

6
Pravila UKV natjecanja / Odg: 9A Digital Activity Contest
«  : 10. Lipanj. 2021, 15:26:16 »
Moglo se ovo riješiti i bez nepotrebne nervoze.

Hoćemo li biti EU ft8 robot krajnje je nebitno.
Podržimo 9a momke.

GG

7
9A microwave contest / Odg: 9A microwave 2021
«  : 10. Lipanj. 2021, 14:50:06 »
E, lako je tebi govorit, makni lna... Ionako san star i gluv, makni mi slušni aparat i di san onda?

Radije iden na brdo iznad kuće pa pomalo.

I ko će krivit one kabliće i sma konektore?

Srediću ja to nekako.

Za AA sve je spakirano😉

8
Pravila UKV natjecanja / Odg: 9A Digital Activity Contest
«  : 10. Lipanj. 2021, 10:24:41 »
Star jesam i ne vidim dobro, ali jedina Opća pravila koja sam locirao na ovoj stranici odnose se na 24 satna natjecanja, a ovo to nije.
Ni u pravilima ta ovo natjecanje nisam vidio da se poništavajtzv unique veze.

Na temelju čega su onda poništene?

Ne bih volio bahati, ali pred koju godinu smo i oko kv natjecanja imali neugodnu situaciju oko primjene pravila i administriranja robotom pa ne bih volio da se to i ovdje ponovi.

Problem komunikacije s odgovornom osobom neće se riješiti ovako.

Nije posao nas natjecatelja da prodajemo proizvide saveza i posve je besmislenom kažnjavati nekog zbog veze koju nitko drugi nije uspio uraditi. Osim ako veza nije održana, a upisana je.
A to je nešto drugo.

GG

9
9A microwave contest / Odg: 9A microwave 2021
«  : 10. Lipanj. 2021, 09:16:17 »
Adam,

To je onaj transverteri koji je bio kod tebe na kanalu, znači DB6NT tvtr, lna i mali qro pa iza njega dg0ve na kojem piše 20w, a ti izmjerilo 50 ;D

Na lokaciji u jn73ws sve bilo ok, a u jn83cw šum konstantno 20 dB iznad devetke.

Čini mi se da je Bert spominjao i notch koji bi svakako pomogao oko neke i band smetnje, a sam filter na 23 cm svakako ne. Ipak mu je passband u MHz.

Za sad čekam i prijavit ću utiske😉

GG

10
9A microwave contest / Odg: 9A microwave 2021
«  : 10. Lipanj. 2021, 07:20:22 »
U razgovoru s OK1TEH dobio sam prijedlog da nabavim bpf od PE1RKI - ima web stranicu s puno dobrih stvari - jer je takav filter i njima riješio problem. Ima dijagram gušenja iz kojeg se vidi propusni opseg i gušenje unutar propusnog opsega - a ono je jako malo, oko 0.2 dB.

Matej kaže da se Bertu može i predložiti malo drugačiji propusni opseg ako u blizini imaš neku beštiju koja ti zagorčava život. JA nemam radara blizu, ali na JN83CW ima toliko različitih signala da je to milina, pa kad se male ruke slože, i kući se otić može:-))

I oni su imali problem s radarom, a sad im nitko ne može ni blizu kad su na JO60JJ.

S dostavom izađe 120 EUR, a možeš birati kakve konektore želiš. JA sam odabrao muški i ženski N, super kvalitete, a Bert kaže da trpe mojih 350W koji još nisu u pogonu. Stavit ću ga ispred releja do antene, iako bi kao bilo bolje iza pred ulaz prijemnika. Ali gušenje je toliko sitno da mi je svejedno, transverter je DB6NT pa ću valjda nešto i čuti:-))

Idi pa vidi;-)

POZZ & CU AAUHF!


GG

11
9A microwave contest / Odg: 9A microwave 2021
«  : 09. Lipanj. 2021, 13:44:16 »
Pozz Dinko,

To s maltretiranju na chatu je postali odurno gubljenje vremena. Maltretiraju te likovi koji pojma nemaju i vabe te da zoveš ili slušaš za qrb ili vezu koja je out u svakom pogledu.
Na nižim bandovima još je gore.

Tebe sam u vezi čuo fondo scala, ali kad si o krenuo antenu nestalo te skroz. I tako te netko davi da ga zoveš ili slušaš, a tko zna gdje mu je antena.

Mi s ruba svemira osuđeni smo na chat. Šta da radimo, trpi i grintaj👺

Pozz svima i ako mi stigne bpf za 23 cm eto me opeT u AAUHF pa kako bude.

73

GG

12
9A microwave contest / Odg: 9A microwave 2021
«  : 06. Lipanj. 2021, 15:16:32 »
Ali veseli pogled na ono nešto crveno bijelo u pozadini😉

CU AAUHF!

13
9A microwave contest / Odg: 9A microwave 2021
«  : 06. Lipanj. 2021, 12:29:35 »
Čim sam upalio uređaj, svbe je bil jasno...S metar na TR751 pokazao je šum od 20 dB preko devetke...
Prije contesta uradio 9A6AR, I4UJB i Ik3GHY, a u contestu samo prvu dvojicu jer je treći bio zauzet na 3cm i gađao neki oblak na zapadu OE.

Imao sam par skedova gdje me nisu ni čuli pa nije imalo smisla noćiti na Promini.

Prilike točno prema prognostičkim kartama... sreća da avioni ipak lete.

Nadam se da su drugi bili bolje sreće.

Iza moje antenice je mrski neprijatelj >:(
POZZ

GG

14
ES / Odg: Es sezona 2021. na 2m
«  : 05. Lipanj. 2021, 07:18:28 »
A moj kume, slabo je kad ne šuška.. biće ti mali šumni broj ::)

Šteta, bilo je tih 4X i na ssb, ali u mikro brojevima kao i svih ostalih, ft8 ne računam, robot modes mi nisu napeti.

Budi uporan i vrati karte za balet na vrime da se povijest ne ponovi ;)

CU

15
Pravila UKV natjecanja / Odg: 9A Digital Activity Contest
«  : 04. Lipanj. 2021, 13:12:02 »
Pokušao sam naći pravila za taj digi contest, ali prošlo me.
Ukidati unique veze je besmisleno i kontraproduktivna, jednako kao i uvjetovati da u plasmanu budu bar 3 postaje da bi prvoplasirani nešto dobio. To ne vidi napretku.

Zašto bi netko ulagao u opremu kad će ga glupa pravila vratiti tri koraka natrag? Ili odlazio u neki portabl? Uravnilovku su i u socijalizmu odbacili...

U vrijeme interneta tih par unique veza se lako provjeri mailom itd.

A čini mi se da i u 9A CW kv contestu ima nešto slično.

Samo dok mi to riješimo, ode voz...


GG



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