MMBX and AFI, please look at post #179 (page 9)
Posts by DM5RM
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Unfortunately all amplifiers are already sold, the last one today at 09:58:24 GMT.
You can still find the item by clicking on "Sold listings".
Hopefully they didn't fall into pirate hands.
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bisonelectronics-sp2jyr offers again the
"2,3GHz RF linear amplifier . 13cm band , 2x BLD6G22L-150BN/2 - ( ES'Hail2 )"
on ebay.
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But why such a big ferrite ?
You have to transform ony miliwatts.
The power to be transferred is not the only consideration.
With method 1a, the entire operating current of the LNB flows through the primary winding.
This can lead to saturation of a too small core.
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Meanwhile I almost believe that it won't work at all.
On the beacon status website
http://www.pa0ehg.com/dl0shf_beacon.htm
is written at the end of the page:
"QRV: always when moon is visible with more than 10 degrees elevation at DL0SHF but only when moon declination is above 20 degrees North"
However, Daniel, EA4GPZ, has reported that he received the beacon on May 16, 2019.
https://destevez.net/2019/05/f…qo-100-station/#more-6594
73 Roland
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Bitte, gern geschehen.
Jetzt könnte man sicherheitshalber noch eine Z-Diode (etwa 12V, ist unkritisch) zwischen Gate und Source ergänzen, damit auch bei Speisung mit +28V der im Datenblatt angegebene Grenzwert für VGS (maximal ±20V ) eingehalten wird.
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you use this link to calculate ?
No, I didn't know about this interesting project yet.
Thanks for the information.
I used Orbitron 3.71 as you can see on the screenshot.
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On the evening of November 7th, a close encounter takes place between QO-100 and the Moon. In Central Europe the smallest angular distance is only about 1°.
This could be an opportunity to receive the DL0SHF 10368.025 MHz EME beacon for a few minutes.
73 & 55 de Roland, DM5RM
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Gute Idee, aber Source und Drain sollten vertauscht werden. Sonst leitet die Substratdiode die ganze Zeit.
Good idea, but source and drain should be swapped. Otherwise the substrate diode always conducts.
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BTW, what is the original connector?
You can have a look at post #179.
On this similar board the connector types are MMBX and AFI.
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Der Magnet stammt von einer alten Magnettafel.
Mein (ausgeschalteter) Verstärker hat ein S22 von besser als -20dB im UMTS-Bereich und nur noch -14dB bei 2.4GHz. Bringt man nun einen Magneten in die Nähe des Isolators, verschiebt sich das Bild am VNA je nach Polarität nach oben oder unten und verformt sich dabei. So war bei mir leider nur 1dB Verbesserung zu erreichen. Angefangen hatte ich mit einer 10mm Neodym-Scheibe, die aber letztlich viel zu stark war. Habe dann nach einem deutlich schwächeren Magneten gesucht, den man direkt mittig oben auf den Isolator kleben kann. Ein sehr kleiner Neodym könnte (evtl. mit Abstandsscheibe) auch funktionieren.
Aber wie gesagt, die Verbesserung ist gering und S21 sollte wenigstens nicht schlechter werden...
Bin gespannt auf deine Ergebnisse.
73 & 55
Roland
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Mit einem eher schwachen keramischen Permanentmagneten ( Durchmesser 15.5 x 4.5mm^3 ) on top kann man die Eigenschaften geringfügig verändern. Bei meinem BLD6G22L- Verstärker wurde dadurch S22 etwa 1dB besser. Mehr Messungen konnte ich nicht machen, der Isolator ist noch auf dem Board.
With a rather weak ceramic permanent magnet ( diameter 15.5 x 4.5mm^3 ) on top you can change the properties slightly. With my BLD6G22L amplifier S22 became about 1dB better. I couldn't do more measurements, the isolator is still on the board.
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Das geht zuverlässiger mit den NB-Baken, die doch wesentlich stärker aus dem Rauschteppich ragen.
LNB mit 12V speisen, auf eine Bake tunen, Polarisation umschalten (18V), Tilt/Skew ändern bis Signal minimal ist...
Allerdings hat diese Feinjustierung bei mir (60cm Offset Dish, GM-201) das SNR praktisch nicht verbessert...
73 & 55 von Roland, DM5RM
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Die einfachste Methode den Tilt / Skew optimal einzustellen ist z.B. mit einem SDR auf die WB-Bake zu tunen und diese dann auf "Minimum" zu stellen.. dann hat man beim NB-Transponder gleichzeitig das Maximum...
Der NB-Transponder ist (V)ertikal polarisiert, der WB ist (H)orizontal polarisiert.
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Hi Alex, that doesn't sound good.
Do you already have any further information, did the FETs survive?
And did you load the output with 50 Ohm before you attached the power supply?
73 Roland
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Here is the picture of my one and only mod so far. The size resp. area of the selfadhesive copper foil depends a bit on the operating voltage.
You should start with a tiny piece of foil and then gradually increase the area until it doesn't get any better.
And don't forget the cover...
Just by the way, with your power supply, you should almost be able to weld
73+55 de
Roland, DM5RM
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Hi, Alex and friends of BLD6G22L,
I first tested my amplifier without any mods.
The original bias control works very well from about 15...30V operating voltage (left PA 10...30 mA, right PA 1.23A, driver stage 0.36A, preamplifier 90...50mA).
The gain at 2.2GHz is about 41dB, at 2.4GHz about 10dB less.
A single small piece of copper foil on the C between W100 and the driver stage boosts the gain at 2.4GHz to 39dB.
It is important to screw the aluminum cover on again before each measurement. Without the cover I had up to 2dB gain change and there is the danger of parasitic oscillations due to unintentional touch.
More than about 20Watt I couldn't generate yet, because my laboratory power supply is too weak.
Some more remarks:
W100/W101 are not filters, but also circulators or more precisely isolators. This is easy to detect, they are slightly magnetic. I wouldn't remove them.
In my opinion the better decoupling of the stages is more important than the possible increase in gain. This could have been a reason for the preamp problems of DB8TF.
The input socket is MMBX.
There are matching plugs: HUBER+SUHNER 16_MMBX-50-2-4/111_NE, e.g. from Mouser. The amplifier cover must be filed off a little so that it fits.
The second MMBX socket is connected to the directional coupler at the amplifier output. An RF power meter could be connected there. I haven't measured this branch yet.
The output socket is AFI.
With an „AFI Plug PCB Bullet“ (Amphenol 920-263P-51P, also e.g. from Mouser) and some 3D printing a cable plug can be improvised.
73+55
Roland, DM5RM
