Posts by DO1OHB

    Hello Holger,


    yes I also had my doubts but it with a simple 100W big old soldering iron (all ESD grounded) it was easier then expected. But the TCXO is relative large and had space around and the TCXO would then be defect I guess.

    Did you use also the 8mA set-up from Leo Bodnars GPSDO and 3dBm?
    No really sure what that 8mA stand for, as the voltage should always be 3,3Vpp on a 50Ohm output...?


    Vy 73, Oliver

    DK8KW , DD1US, team that is really helpful and I will change my set-up accordingly. That make me confident to drive the PA within the limits and to save an attenuator ;-) .


    This attenuator I will use for the GPSDO-Leo Bodnar to the Pluto. Yesterday I had a run and de-solder the original Pluto TCXO and exchange it with an external SMA jacked. I got also the very good hint to solder C124, but after search and find the place I was surprised. Even with glasses and 2,5 Led-lens I was just able to see the place for C124. At least for me there is no chance to solder a capacitor that is below 1mm. I wonder who could do it and how ;-) . Bottom line the GPSDO is now attached via a 3dBm attenuator to the Pluto and working fine.


    Thank you, 73, Oliver

    DK8KW, good point.

    I will take it in account in case I need additional power. Actually I guess the reduced power set-up will be suitable.
    And I know myself setting a Driver to 50% will be forgotten and 100% will be the standard ;-) . But as you said, even in that case the PA will not be at risk, just at the border. I can also confirm that the PA is not running hot just warm, I have a 190x200x12mm massive alu-block in a Alu-Wifi-Outdoor housing. With the PA its just 31mm and fit in the upper side of the housing. So all in one and easy to carry also for portable / Mobil-home set up.


    Vy 73, Oliver

    DD8PL , got my new SG-lab PA V3 yesterday. From the housing you can not see any differences, inside you will not find the 3 bridges for the PTT selection any longer but the new Vox and Pre-Amp. I am starting with the tests, so far it looks very promising.

    I drive the PA with the Pluto, Pre-Amp (CN0417) and 6dBm attenuator at a level of about 14dBm, input should typically be 40mW or 16dBm. I measure now a forward Voltage of 3,1V (from 3,5V at 20Watt).
    Further tests are ongoing. This new PA will reduce my effort significantly (can remove the EP AB003). ;-)


    73, Oliver

    I think the CN0417 is rated 1 watt so should be good for driving the SG Lab PA, so I did Pluto=>SPF5189 Amplifier=> 3dB attenuator=> CN0417=>SG-Lab PA . This would need less space than using the EP-AB003. I think the PA output is about 17W but can't measure accurately, but is enough for me.

    @G4MBQ , the CN0417 get 0dBm from the Pluto and increase it to around 20dBm which is 100mW not 1 Watt. As this device is powered by a standard USB port the entire DC power consumption shout be max 2,5 W on 500mA . So you can drive with the CN0417 direct the new SG lab PA version 3 as this new PA require 40mW (only an attenuator needed). For the version 2 device of the SG-lab PA you need an addition PRE-PA (I took the EP-AB003) to bring it to 500mW. The EP-AB003 is too strong for that job but worked perfect. Other Pre-PAs can do it maybe more efficient and are smaller and cheaper.

    'Specification RF Amplifier 2400Mhz Analog CN0417

    Frequency range: 2400 - 2500 MHz

    Maximum gain: +21dB

    Impedance: 50 Ohms

    Max supply voltage: 5V / 370mA

    With circuit: ADL5606 and LTM8045

    Insertion loss: 0.4dB @ 2000 MHz


    Bottom line, I guess getting 1Watt output instead 100mW will stress the CN0417 too much. It runs hot even with 0,1W.

    73, Oliver

    Hi Andreas,

    this is a great solution as my CN0417 was the 'hottest' device in the set-up.

    Especially the TX chip on the backside even when cooled with a little Raspberry-Alu-block.

    I guess I will follow your solution.


    Thank you!!

    73, Oliver

    Hello Matthias,

    I will use the Leo Bodnar single GPSDO as well. How do you connect it to the Pluto.
    Actually the most reasonable hints are:

    a) install a 18-27pF Capacitor (C124 , not used in unmodified Pluto)

    b) 3dBm SMD attenuator in the line to the Pluto (removed TCXO)


    How did you do it in practice?


    73, Oliver

    PC5E , the 12V from the car battery is a good argument, when I will be on tour I will use the 220V from my mobile-home ;-) . So yes, requirements are key and could be very different.


    Regarding the TCXO-Mod, I bought a lamp with 90leds and a 2,5x lens. Even then it would be a tough challenge. I installed the TX-Mod on the Pre-PA (EP-AB003 WIFI), just a little bridge between two chip contacts. It worked but I realize that I get older ;-).

    I saw some Plutos with TCXO mod on ebay but relative expensive so I decide to take a risk and challenge.

    Hi Robert,

    during my test I had it some times. I remove the power from Pluto (in my case USB), shut down the SDR-Console, restart the PC, started the SDR-Console, ensured the bandwidth was in TX range during the Pluto selection (USB) and it worked again.

    Not sure what the reason issued the problem but it worked again.


    73, Oliver

    The best 13cm bandpasses for hamradio (as far as know) are the interdigital filters made by DK2DB (check his shop)

    Wow that DK2DB-solution is rock solid and the measurements are impressive too.


    Out of the information above you strongly recommend a band path also between SDR and the CN0417 (first pre-amp). Got it. Thx.


    73, Oliver

    Hello Robert,

    your set-up plan looks nice. I have basically have/will have the same, so allow me some comments:

    1. RF band pass filter is always a good item but the CN0417 have one inside so it would be better to have a band-pass behind the last PA (but then you need a stronger one) - I have the same point and not sure how to fix.

    2. Power Management. The PA (with the highest power consumption) require 24V-28V. So my idea was the other way around. Meanwell 24V-90 Watt external Power supply (MW GST90A24) with two DC-DC buck converter (DEBO DCDC 25W) . One for 5V (as they are adjustable I go to 6,7V and then on a 5V voltage regulator (5A) LM 1084 IT5,0 to be sure that the DC-DC have 100% the right voltage and not higher voltage on the start). The second DC-DC for the BIAS 12/14/18V as required. Actually I have another Pre-PA EP-AB003 for 12V - will not need it with the new SG-PA V3. The DC-DC converter have a low load guess 1A for 5V and 0,5 A for 12V, so they stay cool.

    3. I guess you will need a frequency-stabilization for the Pluto (either TXCO exchange inside the Pluto) or external GPSDO. I will go with the GPSDO (another 5V for the DC-DC). This stable frequency could be used also for the LNB. Actually I am looking how to bring this frequency to the LNB cable (one cable solution like AMSAT-downconverter).

    4. The new SG-Lab PA V3 require only 40mW input (max 100mW) so you need an attenuator between CN0417 and PA (guess -6dB). I will get the PA in the next weeks and start with 6dBm, 3-5dBm for maximum output. As the PA have enough power (15W), also with 24V, it will not be an issue.

    That are my ideas around your question.


    73, Oliver

    Sorry OMs, möchte hier nicht zur Verwirrung beitragen oder den Thread high-jacken....

    Nur wenn ihr nichts dagegen habt...

    @DH2VA , bei USB Betrieb habe ich nur eine 5m (USB-Verlängerung) oder 1m USB Kabel angeschlossen, keine Stromversorgung und es funktioniert. Nutze ich LAN so ist eine Stromversorgung (Meanwell 24V auf DC-DC 6,7V auf 5V Spannungsregler) im Einsatz. Die 5V sind dann für Pluto/CN0417/später GPSDO.
    Ich habe noch kein HW-Mod am Pluto durchgeführt. Macht es Sinn die USB-Ports auf Masse zu legen (oder L7)? Bin da noch unsicher.. Könnte auch für Wilhelm interesant sein?


    73, Oliver

    @dl6dca , Robert,

    if you find a solution please let me know as well.

    I have the Pluto on USB and it works as it should. I connect the Pluto with LAN and RX worked fine but on TX I realize interruptions during sending e.g. a USB Tone with SDR-Console. No such interruptions during TX via USB.

    I checked it with the Pluto on the RX path.

    I am helpless and using the:

    UGREEN USB Netzwerkadapter USB 3.0 auf RJ45 Gigabit Ethernet Adapter für Macbook Ultrabook , Windows 10, 8.1, 8, 7, Vista, XP usw (Schwarz) which was suggested to use in a youtube video from US.

    Any idea or hint?


    73,Oliver

    PC5E, Robert, I guess I will start with a 6dBm attenuator as the power is much as sufficient even with 24V (that is the voltage I use). Then I am on the safe side, 2dBm more or less will not make a huge different (in that range) but could set the PA at risk. I guess with 40mW input you need to be carefull.......


    73, Oliver

    Hello Robert, I use the Pluto with the Pre-PA from AD. That match to the Pluto and I order both together. It is the CN0417 from AD. I ordered in US and get it within 4 days and relative cheap. This PA have already filter for 2,4Ghz and bring the Pluto to a level of about 100mW around 20-21dBm (that is what I measure). From that you can drive the SG-Lab PA V3 as this need just 40mW, so just one small attenuator. I ordered the new PA and will test when received.


    73,Oliver

    Team, maybe you can support/answer my question as well.
    I have the Pluto on USB and it works as it should. I connect the Pluto with LAN and RX worked fine but on TX I realize interruptions during sending e.g. a USB Tone with SDR-Console. No such interruptions during TX via USB.

    I checked it with the Pluto on the RX path.
    I am helpless and using the:

    UGREEN USB Netzwerkadapter USB 3.0 auf RJ45 Gigabit Ethernet Adapter für Macbook Ultrabook , Windows 10, 8.1, 8, 7, Vista, XP usw (Schwarz) which was suggested to use in a youtube video from US.

    Any idea or hint?


    73,Oliver