Posts by DM4DS

Quote from PA1RW

Hello,

I found some pictures on twitter.

73, Dolf.

Interesting to see here my pictures 🤔🙂

But that´s not the main reason for my posting.

I tested the external ref and it works like it should. The CLK_Out is activated after CLK_Source is set to external.

Also the PTT works if you set the "adress" correct.

not made deep tests while busy with other things but thought it could be interesting for other to hear good news.

PROCEDURE:

use Putty or what you prefer

login with 'root' - 'analog'

fw_setenv refclk_source external // this enables the CLK_IN/OUT

pluto_reboot reset // reboots pluto and the CLK_IN is active

If your reference is not perfect you can correct it with:

fw_setenv xo_correction 39999750 // for example

Changing the frequency is done with:

fw_setenv ad936x_ext_refclk '<25000000>' // You must use ' NOT " as describes in the WIKI since 0.32!

Or you use: fw_setenv ad936x_ext_refclk_override '<25000000>'

Don´t forget to reboot the Pluto to apply the changes with:

pluto_reboot reset

Easy and fast done.

Hope it helps.

Greetings

Sandor

As last solution, if you stuck, I can offer my help.

Distance is a problem but if you send it, I can try my best.

Received in the past 6 "dead" plutos and only 2 were really dead, the other 4 are working again. 1 with a squirrly signal but it works If it is really dead, I can send you a complete "new" moddified one if you want. TCXO, GND, PTT , whatever you need.

Write me an eamil and give me some days, I do not check every day my mails.

Hope I can help

73
Sandor

DM4DS@gmx.de

We spoke in the whatsapp group , i gave you the 10ohm ....

Hello,

Received today a DUR-Line +Ultra Quad LNB and it is a PLL with RT350.

The Crystal is on the TOP side with 25MHz.

Horn diameter: 52,5mm with plastic

Mounting dia: 40mm

The cover is 4mm deep , enough space for parts

Also received the QUATTRO Version which is a PLL too!

Greetings

Sandor

DM4DS

Edit: Forgot Cover pics

Edit 2: inserted pic Quattro inside

If someone needs small PCBs for BiasCircuit. I have some PCBs left with LP2951, which I have and can send with the package.

Only the Paint must be removed from the Vi,Vo, GND areas on some as you see on the pic.

Cap Filter?

I´m very happy with mine
Build after reading: http://www.ko4bb.com/ham_radio/Pipe_Cap_Filters/

I´m using 2 of them and love em.

vy73

Sandor

Thought IU2KAC wants the Pluto in his LAN. Then the hardware is the wrong one. Thats why i posted before, but now it looks that he just wanted to extend the USB, then its ok.

About extender:

I tested an extender too , bought it for the LimeSDR.

It´s a direct connection like USB, but with an Network cable as extension .

The Pluto/Lime or whatever isn´t available in the network like it is if connected via a USB / LAN Adapter to your local network, cause it isn´t in the network. (Lime does not support direct LAN)

My adapter as passive (without 5V extern) and worked over 5m LAN cable without problems. Took a standard CAT7 cable between, without configuration and it works. While the LimeSDR supports USB3 and my adapter don´t , i stopped experimenting.

In my opinion, on a Pluto, the USB/LAN solution makes more sense if you already have a LAN. Then the pluto is from everywhere available, from Smartphone, tablet, PC, notebook etc. Also if you have a "server" running or super fast internet, from the WAN. The bandwidth is massive it needs, don´t forget that.

Maybe you wanna try USB/LAN with your pluto IU2KAC...

sorry that i write in english. Also not my mother language but much better than my italiano

Have a good time and stay safe!

A small help could be the german PDF.
You can translate sentence by sentence and fill in your things and make the X at the right spot

https://amsat-dl.org/wp-conten…/02/AMSAT-DL-Beitritt.pdf

Maybe Peter has a english form

vy 73

Sandor

Hello

I can´t read the first post but i think he tryes to config PLUTO for LAN usage.

You are using the wrong Hardware!
This is a USB Extender , not a USB / LAN Adapter.

It´s to make a USB "longer" via LAN cable . Not to adapt LAN via USB.

Greetings

Sandor

Over the last 2 months I worked on the amp, original designed by PA3AXA, Rens.

After eliminating all problems and a lot of optimizing after pimping the amp, I am proud to say: It´s done.

The "next" version of this amp is running smooth and cold, with less current, lower Voltage but much more gain.

Gain: 60dB , up to 66dB (minimum ~55dB)

Rated constant output: 20W (SingleTone)

Max Out: 30W but thats overkill even with low currents!

Max input: ~15dBm! (Pluto has +3dBm @100% drive)

It´s super linear up to 80% of its power. Hope Matthias DD1US can catch a sample to go deeper into measurements than i can do with my siglent SSA3032X analyzer. But psst, he doesn´t know that

The plan is to build up to 15 pieces. Ready to use with 12V + 24V (22-28V).
The 12V can be used as PTT or running 24/7. The heat with low currents isn´t high.

Its mounted on a heatsink but for long term use, you should place a fan on the heatsink.

If you are interested write me an email: dm4ds@gmx.de (please give me 1 2 days for answer)

I hope to update my homepage soon with more informations and pictures + Videos of the measurements.

Here are some pictures: while the minimum of my TG is -20dBm I inserted an extra 10dB attenuator.

the PCB

Case all will be build

Case

MAXIMUM Output with -13dBm input!

After 10 minutes passic cooling @20W constant output sweep

Quote from dk1za

Thanks 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

Display More

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....

Quote from DF2HF

Hello 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

Display More

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

Here is my video about the 0.2ppm muRata TCXO change on a small PCB...

Also the much easier GND Mod for LAN use.

Are you really paying 4€ per qsl?

I know , a stupid question but I must ask.

But what is more interesting for me: if yes, why?

Quote from HB9SKA

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.

@RK3DJW :

At 100W Output of the PA , i measured 16,5A @28,1V

vy 73

DM4DS

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

--------------------------------------

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!