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What power levels are some people using?

PostPosted: Fri Nov 29, 2013 10:04 am
by M0SAT
I find it sad that after all the work and effort the team have gone to in getting FUNcube built launched and operational so quickly after launch that some operators are clearly ignoring standard satellite operating procedures.

Tuning is and will be an issue until the Keplers are sorted and even then people still tuning in a rather cavalier fashion across the transponder looking for their uplink signal. It took me 4 days to find mine due to the busy transponder and not wanting to flatten other operators QSOs, but others appear to have total disregard to this.

Last night what I found even worse was when FUNcube was North of me (I'm in IO91, NW London) and there were operators much further South than me (QED much greater distance to the satellite) who were the strongest signals on the transponder. As a test I upped my transmit power to ask them to reduce power and even at 20 watts (I stopped at this level) I could not be heard over them. So what power/ERP are these stations running? It's crazy. I have a 9 element for 70cm uplink and don't usually need more than 5 watts to access.

On a brighter note there are many operators who do seem to be operating successfully and it has been nice to have QSO's with old friends and new.

Thanks once again to the team

Dave M0SAT

Re: What power levels are some people using?

PostPosted: Fri Nov 29, 2013 2:18 pm
by 2e0sql
Dave,

I'm using similar power levels to yourself 5w is normally plenty but if some higher power stations appear I'm having to increase it to 20w which is a bit of a shame.

Antennas are wimo X-Quads.

Re: What power levels are some people using?

PostPosted: Fri Nov 29, 2013 4:25 pm
by wd9ewk
M0SAT wrote:Last night what I found even worse was when FUNcube was North of me (I'm in IO91, NW London) and there were operators much further South than me (QED much greater distance to the satellite) who were the strongest signals on the transponder. As a test I upped my transmit power to ask them to reduce power and even at 20 watts (I stopped at this level) I could not be heard over them. So what power/ERP are these stations running? It's crazy. I have a 9 element for 70cm uplink and don't usually need more than 5 watts to access.


It's similar on this side of the Atlantic. Especially earlier this week, there would be some running what should be considered excessive transmit power. There have also been passes where I couldn't hear any one station running excessive power, but maybe the number of stations trying to get through the transponder meant I couldn't hear myself.

I run no more than 5W transmit power. My all-mode satellite station has two FT-817NDs and an Elk Antennas handheld 2m/70cm log periodic. On one pass earlier this week, I was able to cut my transmit power down to 500mW during a QSO and could still hear myself clearly. This is just like working VO-52, and that's a good thing.

M0SAT wrote:On a brighter note there are many operators who do seem to be operating successfully and it has been nice to have QSO's with old friends and new.


Same thing here.

We have had 3 other satellites where you could work in SSB or CW before FUNcube-1 was launched, but the operators have come out to work the new satellite. It is fun to hear others on passes around 11pm or midnight local time, when on other satellites I would probably be talking to myself for 10 to 15 minutes - if I happened to set up my gear in the yard at those hours.

73!

Re: What power levels are some people using?

PostPosted: Fri Nov 29, 2013 4:46 pm
by OH2FQV
Hello both, Dave and Peter.
I have used 5w ( my minimum level and cable loss about 2dB ) with 10el yagi, seems to be well and far enough for this sat.
I did tried for empty pass with my high power, 40W and either its causes rfi to my 2m or then satellite didnt like of it, as downlink audio got a bit garbled. Driving too much dont give much benefits, as we know.

South europe seems to be place with powerfull stations and lots of rfi and havoc at satellites.... ;o)

:Jari

Re: What power levels are some people using?

PostPosted: Fri Nov 29, 2013 5:40 pm
by g0mjw
Hello All,

I am running 5W minus about 3dB cable loss - but into an 18 element LHCP yagi. That's the minimum power the TS2000 can put out without messing with ALC and seems about right. I try and keep an eye on the beacon level and keep below it. I noticed on last nights pass that there were people tuning up and down and looking for their signals, sending dots or "Ola". This QRM stopped just after half way through the pass, so either the QRM was mainly from the South or it was just a co-incidence. I don't think this is deliberate - it might be a function of the spin of the satellite or simply people who can't hear the satellite very well setting their power so they can hear their own uplink.

There is something odd about the dpooler prediction from the keps - SATPC32 is tuning my uplnk and downlink but I constantly need to correct it on the uplink +-2kHz last time.

Mike

Re: What power levels are some people using?

PostPosted: Fri Nov 29, 2013 9:12 pm
by WB4SON
I'm running 30 watts out, with 4.8 dB of loss (cable and SWR) at 435 MHz. Therefore at the antenna, I see 10 watts. The antenna is a M2 Eggbeater. Because the performance of an Eggbeater falls off near the horizon, it has a theoretical gain over a dipole of 3.2 dB despite being fairly omnidirectional. (In my mind it should have zero gain if it was truly omnidirectional).

In reference to various 70 cm beams, I am the equivalent (In round numbers) of 2.6 watts to a 7-element beam, 2.0 watts to a 10-element beam, or 0.9 watts into an 18 element beam.

I'm not the strongest signal on the bird for sure, but I'm above the noise level and seem to be doing OK. So I'd say that the transponder on AO-73 is pretty sensitive.

I remember from the old days, when a satellite came into view, my RX noise level would increase. I don't notice that with AO-73, so I wonder if their system noise to the transmitter is lower?

73, Bob, WB4SON

Re: What power levels are some people using?

PostPosted: Sun Dec 15, 2013 10:15 am
by G3XJI
Sadly it's just another example of the "must have at all costs, with complete disregard to others" society in which we live.
Listen to any dxpedition (if you can stand the racket!) and you will see what I mean.

Regards to all.........G3XJI