Someone take care about power regulation ?

  • Many people built and assemble parts to be ready on Es'Hailsat-2 for TX. But there's still a question : Are you able to apply a power regulation to avoid

    angry "Leila" on your signal ? In my opinion most of Oscar-G1 operators try to do this regulating power on the transceiver. May be a way. But there's some some difficulties because for example TS2000 has a 5 W minimum, power on VHF and UHF (may be 4 4,5 w).. For several devices you need to reduce power form 40 to 45 dB. If you want to do a regulation thru power regulator of TS2000. its clear that you need reduce more decibel. Same issue with the amplifier. The Surplus market usually provide amplifier that accept maximum 13 dBm. My BU500 has an output of 0,5 W (or more depending to the driver power). Another issue to solve, another attenuator to insert between amplifier stage and the converter.... Some one has solved theese issues or have find a solution ? I've some doubt about commercial systems too, but this is another story...

    .

  • Hi Allesio,

    I found a 29db "rf Florida" chip attenuator in the surplus.

    So I can drive the BU-500 with my TS-2000 using max. 20W. It will give about 0,3W out for the SG-Lab Amp -> ca. 15W max. out

    So I can regulate between 3-15W on 2,4GHz (5 to 20W from the TS-2000).

    If 3W is still to much, I can use the 0,3W from the BU-500 :-)


    73

    Michael

  • ik4idy :


    I use a similar switchabe attenuator like this to get the 1W from my Yaesu ft-790 to the needed input power for the BU500.


    Be carefull with the output level from the BU, the build in bandpass will only accept max 0,5W out.


    vy73 DB8TF


  • Yes Flo, you are right. Surely i keep the power under 0,5 W. It's an issue but we try to do this..;)

  • Lately i saw some SMT lowpass filters for 2,4GHz on eBay (from the UK) which are capable of handling 3W power.


    Maybe they could be installed instead of the weaker bandpaß devices.


    It would be nice to get 2W drive from the BU500 for my little MRF21045 ;)


    vy73 DB8TF

  • I'm oriented to reduce power like OE7DBH Darko has done in youtube video. ..But i've a power budget too high in 2 mt band. I've an idea for trying to reduce power on TS2000, on the settings. I'm not interested to have full power on 2 mt, and I have skills to try some adjustment on the hidden menu. If I will have good results, I will publish it in some way.


    73.



  • Available in 20dB and 30dB as well from Ebay. Not really precise (11.4dB vs. 10 dB advertised) but simple and robust solution, so my favourite. After all, you only need to set the power once.

  • I am just not building such a ridiculously overpowered station that I will need to reduce my power by 40-45dB. That should fix it without problem.

    Similarly, I am not immediately considering those WiFi amplifiers just for that reason. I now have about 2W available from an SG LAB transverter so I do not need an amplifier that makes 20W from 10mW input. I need like 10-13dB gain in my amplifier, not 27-33dB as those amps usually offer.

    So when I use one of those, I will either modify it or fit a fixed attenuator in front of it, not use my transmitter output control to provide this attenuation.

  • not too much words - just a photo. With this, I was quite succesfully during L/S-mode on AO-40- made a lot of tests with DJ1KM. In perigee we wkd sometimes with just 400mW out. Adjusted by the attentuator on 144 MHz, checked with EME powermeter - see below


  • A very effective attenuator for SSB is a feature almost all (modern) transceivers have: 'MIC GAIN' ; -)

    Yes, I know. But with mic gain you have major risk to cook your converter if you forget to setup it when you come from terrestrial ssb ! :( Ok I guess you are saying :But it the same if you regulate power, if you forget to lower the power you have the same result... ok but I'm confident that this solution (regulate KW TS2000 power) is more secure than mic gain...

  • not too much words - just a photo. With this, I was quite succesfully during L/S-mode on AO-40- made a lot of tests with DJ1KM. In perigee we wkd sometimes with just 400mW out. Adjusted by the attentuator on 144 MHz, checked with EME powermeter - see below


    professional way to solve...may be the best solution.

  • pe1chl

    Hi, did you acutally measure the transmission power from your SG LAB transverter, or are the 2 Watt specifications from the manufacturer?

    It is the spec, I did not measure it. I only checked that the signal is clean, and it is.

    But when it is less, it only improves the situation.

    What I mean is: I read all the time here how people have 2 or 3 meter dishes, and build 100W amplifiers, etc. That is of course the way to get problems.

  • Flo, I think pe1chl tries to make another point. For an active NB-transponder usage it is by far not necessary to have a moonbounce capable uplink. Last Sunday during the Microwave Meeting in Heelweg (Holland) a friend of mine stated: 'They have EME stations for 13cm , but we never hear them?' ; -)