What TX amplifier do you plan to use?

  • hello together I am also interested in Es'hailsat


    I have a PA with MRF 21030L I use for DVB-T makes a maximum of 14 watts at 2.4 watts input at 27 volts at 2370Mhz

    Have the PA on a HAM market bought by someone who has Modified for 13cm look what he did. I think your MRF is more powerful

    I hope it helps you a bit

    For Uplink to Es Hail i want use another PA


    73 Klaus

  • It´s interesting, what´s in use by other stations. My situation is quite comfortable, as I will make use of my 13 cm EME rig: Kuhne MKU 23 G4 + driver + MKU PA 23130 with solid 75 W into a 3 m mesh dish. Optionally I will reduce the power to an appropriate level or turn the dish away a little, to lower the signal strength at the satellite.

    RX will be done by a separate 80 cm dish and a LNB with a RTL-Stick.

    I wonder, if anyone of you will become active in the terrestrial business on 13 cm like tropo and aircraft scatter as well. It would be nice to try.

    I hope to hear you via the bird at least!

    vy 73 Andreas

  • I still have a nice linear PA, Mode A! from Comcast, former used in an Australian VSB TV Distribution Network , for using with Es'hail Sat . It is interesting that the engineers where able to combine 5 Transistors in a 3 double combiner network (I never had seen such a solution before).

    As I mentioned before , this is a class A amplifier with about 2A per final Transistor. It delivers a loot of heat for 17db gain . I am looking forward into the future with practical Es'hail experience, how linear this linear PA will be behave with DATV. Maybe I can reduce it to something like A with a little B, as every transistor has ist own poti for adjusting the drain current.

    vy 73 Hans

  • Hello Heiner,


    is this the actual PA you are using ? As far as I can see there are no significant changes especially for "matching" to 2,4 GHz.

    I just ask, because I have the same PA in "original" condition and I also want to modify it for 2,4 GHz - I do not need the first stage, but the HP-stage.

    The hints in the WWW concerning modifications of this PA to 2,3 or 2,4 GHz all included changes in the matching of the transistors (pieces of copper and/or capacitors added).


    73 de Johannes

  • DL5RDI Johannes, there are two modifications in the internet. I choose the one like on the picture. I will attach the link here. this modification is from the overall approach the best out of my view. The added copper pieses discribed in the other approach my be needed in addition. My PA is under construction at the moment. I will post pictures and measurements soon.

    http://emejo80jk.cba.pl/Techni…na%20pasmo13cm%20wer1.pdf

  • Hello Heiner,


    thank you for the link. I am very intrested in your experiences with the modification. Please publish here your pictures nd measurements - I will try to "copy" your work in my PA ;-)


    73 de Johannes

  • During the vacation I debug the base station power amplifier, remove all of the filters and couplers, dismantled the power synthetic part of the device, in the late stage using only a MRF6S21100HS.Replace the circulator of 2400-2500.Now can be a very good job in 2.4 g.In the case of the input - 20 db can output power of 47 db.Now also need a good narrow-band chamber type filter.I bought two at a flea market, the hope can be adjusted to the needs of bandwidth.

  • Inject about 100mW on the input and measure the output power.


    Now use small pieces of copper foil on the input pcb trace for max output power and then add a small piece on the output trace. That worked best for me. Abt 16W with 0,5W drive. Takes some time but works.


    First i tried with a network analyzer to optimize S11 on the input but then i only got 3W max out of that little PA.


    vy73

  • I bought two of these.. looks very straight forward the design. The bias voltage could be set via I2C pads. and also the price is very good.. There are more available..

    Hope next week I can post first results here..