Hi Rasto, the big gun must have 20dB more than me, 200W into a 1.2m dish or so. So stupid, so sad... regards Mike
Russian native speaking pirates on FM freq 873. No names no conversation, just talking garbage. Obviously intention to cause QRM.
Unfortunately still the irresponsible fool who in FM with a very strong signal is making QO100 unusable !!
Display MoreThanks Sandor,
I will check tomorrow and will report. I have an idea what Rs you mean. To be sure it would be helpful if you could make circles around the Rs in the picture of your PA.
Have a nice weekend
Walter
DK1ZA
I first have to make a picture from the repaired one.
The "old" one is no longer in use while the PCB traces burned after more than 35W on DATV....
Display MoreHello everyone
I faced another weird issue, but this time on another amplifier.
The idle current should be around 1A, but it's only 6mA !!
When I touch the gate of the transistor at the top of the picture, the current increases to 1A.
What can be the issue? I'm checking all the connections. The only thing I can think of is a loose connection to ground somewhere.
Any ideas?
Bests
I received a different Amp with the "same" problem.
The problem was quick found . It has nothing do to with the doherty or what ever. There are small 10Ohm R between the 28V and the Bias of each Transistor and they were "burned" . They are not complete dead, they are 50kOhm and so the voltage is wide too low.
I soldered in new 10Ohms (5 on this one here) and the complete amp is working excelent. Nothing on the doherty was changed!
Measure them on yours and i hope it´s the same on your side. You can measure them inside the AMP, no need to desolder them . 10Ohm or 50kOhm is a wide range and your Multimeter can this
Have a nice weekend
Sandor
DM4DS
Just "clicked" a 3D printed raincover on my selfmade POTY.
It does not fit the kit version, cause my reflector is round.
The loss is so small that i do not recognize it.
Can be found on my thingiverse.
[Blocked Image: https://cdn.thingiverse.com/renders/d1/08/74/02/0f/84f5460cdcb050f74e4befdf964cddce_preview_featured.jpg]
Um nochmal etwas von einem sehr frühen Post aufzugreifen: MegaSAT LNB
Benutze selbst in einem Setup das MegaSAT Twin bzw. Quad Diavolo ( Diablo ) LNB. Beides sind PLL LNBs und haben in meinen Augen einen tollen Vorteil, wenn man auf externe Referenz "umbauen" möchte.
Beim MegaSAT LNB sitzt der Quarz direkt mittig zwischen den F Buchsen (bei der Twin Variante). Dadurch ist es sehr leicht möglich, eine F Buchse zu kapern und für externe Speisung zu missbrauchen. F Buchse von der Platine getrennt, kleines C und 1,5cm Kabel zum Quarz, fertig ist die Huckepack Lösung fertig. Platine muss dazu nicht aus dem Gehäuse!
Der LNB läuft dann entweder auf dem internen Quarz, oder wird ab einem externen Signal von -20dBm "überstimmt" und steht so gut Eure externe Referenz ist.
Grüßchen
Sandor
Here is my video about the 0.2ppm muRata TCXO change on a small PCB...
Also the much easier GND Mod for LAN use.
How do you inject the sound into the TRX ? Via interface or from loudspeaker to microphone ?
Via Sound Interface from PC to TX
Or via VAC (Virtual Audio Cable) if using a SDR.
Update:
the amp burned all PCB trace behind the combiner after 30 seconds on DATV with ~35W.
Flo tried to repair it but was not able to do. Now it´s running only on 1 Transistor and running ~35W with very bad efficency.
I modified myself another one and this one is doing 150W @ 28V @ 16A without any problems.
Greetings
Sandor
DM4DS
Old Post
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Today i got the PA from DB8TF - Flo back . Amazing.
Pictures #225
First QSO was with Flo and its fantastic. For SSB it´s quick too much power with my 1.2m dish. I think it´s easy to trigger LeiLA , we didn´t!
In KG-STV super clear Eye-diagram.
After i figured out how to stream the small ksyms, i´m good for some DATV
Thanks again Flo. Surprise follows!
