Posts by DO1OHB

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

Hallo Andreas,

ich schicke Dir auch meine mail-Addresse und bitte ebenfalls um deine Datei.

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

DL1GNM, yes you are right and I use the Pluto SDR so the V3 would be easier to implement. The Pre-Amp (CN0417) will make around 21dBm so at least an attenuator with 6-9dBm need to be installed.

73, Oliver

Hi Mike, very good solution. Thank your hints and tips.

73, Oliver

Hello, I ordered my PA two weeks ago, unfortunately the V.2 with 500mW to drive the PA.

73, Oliver

DH2VA and DB8DT, thank you for the feedback.

For me the easiest way would be a coax attenuator from the GPSDO to the Pluto prior TXO-Chip pins.

Do you know which level would be the right one (Leo Bodnar GPSDO xxmA level and the related attenuator in dB)?

73, Oliver

Quote from DL5CN

The goal must be to find a transmitter chain without unneccessary intermodulation. The Pluto followed by the CN0417 delivers +20dBm
(100mW) with good linearity.
@Oliver: Why don't you stick all the attenuators together and place it behind the last amp? With 36dB of gain of a two tone signal there is no danger for the attenuators. From 0 dBm of the Pluto you achieve 36dBm PEP (4 Watts PEP), the 2 W dummy load will withstand it keeping the transmission short. I would try to bring an damped signal back to the receiver to control intermodulation.

73s
Andreas

Hello Andreas,

I try to keep drive the PA EP-AB003 with 5-15dBm input signal to be on the save and linear side. So Pluto =>CN0417 => attenuator ( to drop in the right entry level of 5-15dBm) => PA EP-AB003. I need about 500mW from the EP-AB003 to drive the final PA (SG-lab). SG-lab PA is ordered and should come soon. So I have different ways to keep the devices in a stress free and linear level. You are right I could also have the attenuaor behind the EP-AB003 but then I burn the power instead of smoothly control it . Hope I am right .

Hello Mike, great set-up, congratulation!!

If you allow...just 2 question:

1. How did you connect the GPSDO from Leo Bodnar to the Pluto (any attenuator ? or straight? 8mA set up for the GPSDO?)

2. How do you realize the PTT?

Thank you in advance,

73, Oliver

Back to the question: Can a Leo Bodnar GPSDO (with 8mA set-up) directly substitute the original Pluto TXO?
I am in front of the same question. I guess DJ0MY is right, it should be ok and not too strong.

Please correct me if I am wrong:
- 8mA on 50Ohm are 0,4V ==> 0,4*1,414 = is 0,566Vp ===> 2*0,566V= 1,13Vpp so close to 1,3Vpp which the Pluto require.

Right?

Quote from HB9SKA

500 mW is the maximum input power as I know. But this are guessed values.

Hello Thomas, 500mW or 27dBM as input for the WiFi booster is much to high. Best range is between 9-15dBm (optimum) or 8mW to 31mW.

So from my point of view a good result would be at 29dBm or 0,8W behind the Wifi PA . If you trigger the PA with 20dBm (max) you could achieve 34dBm or 2,5W but this is working on the edge. So the truth is somewhere in the middle of 0,8W (proper level) and 2,5W at the highest.

I believe (measured) 14dB gain is realistic while 17dB is a bid optimistic for that device. That is the reason while I ordered a PA from Bulgaria and use the WiFi PA as driver

73, Oliver

Hello Peter, yes that graphs make it very clear. I guess I need to get a larger dish, at least for RX.

Thank you Mike and Peter for your comments.

Quote from G0MJW

Buy a NanoVNA V2 - thay are about €60. Then you will have the test equipment to set up a helix or POTY. Either will do, obviously I prefer the POTY. A 45cm dish is quite small, it would be better to get a larger one if you can. You may need a little more power than the typical WiFi amp can deliver.

Mike

Mike, I am the 'proud' owner of an NanoVNA-F, just 2month old, but that is basically limited to 1,3GHZ. So the VNA 2 runs up to 3GHz, what a pity, outdated with Nano-F in only 2 month . The 45cm dish is also planned to be mobile, a SG PA is also ordered to ensure the right/better sufficient power level.

Peter, for the home shack I will use a 60x90cm 'Gitterantenne' for WiFi, it was relative cheap with 45€ and require no VSWR adjustments. Unfortunately I have not reach the satellite with the current set-up (TX should work, antenna not sure). RX up until now just with web-sdr in UK. Thank you for the hint regarding 60-80cm dish for RX.

73, Oliver

Dear all,
I am working on a TX part with the pluto and Pre-Amp and Wifi-Amp.
I am not sure which antenna will be the best for a small dish.

I will get a 45cm Offset dish from Technisat within the next days. (technisat 45 digidish).

What will be the best solution:

1. Helix or

2. Poty

- plan is also to have the RX solution in once (next step)

- have no equipment for measurements on 2,4GHz

- best will be a ready to use antenna TX/RX solution or at least a DIY without adjustments

Any good hint?

73, Oliver

Hello Thomas,

I cascaded the different attenuator (3) as I started with the Pluto Output of 1dBm followed by -10dBm (1.) attenuator, so -9dBm, followed by the CN0417 (+21,8 dBm) and (2.) attenuator of -20dBm. We are now at -7,2dBm. This signal goes to the EP-AB003 (+14dBm) and the final (3.) attenuator of -9dBm so I measured at the end -2,2dBm.

1dBm -10dBm +21,8dBm -20dBm +14dBm -9dBm = -2,2dBm (red =attenuator)

The challenge is to keep the signal in the input range of the amplifiers but below 0dBM for the RF 8000 at the end. The attenuator have only 2W so I have to be careful after the PA.

73, Oliver

I just received the RF 8000 Power meter from China after 2month at the weekend. I also ordered several attenuator from 3dBm to 40dBm.
This little device is very sensitive (input max around 0dBm) and the best results (low error rate) at -5dBm.
I was able to test the pluto, the CN0417 and the EP-AB003 step by step but also the entire end-to-end setup. The result was pretty much in line with the projected gain from the supplier, just the EP-AB003 show a bid less gain 14 vs 17 (but this is obviously normal ...

As I have no calibration tools I mixed the different attenuators (also not calibrated) but it seams all n a range of +- 1dBm. So not precise but for me more then good enough.

73,Oliver