Open Research Institute Ham Expo March 2021, 26 Sep 2020

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From YouTube: 05 Symposium 2020 Portabel Station for QO-100

Description

AMSAT-DL Online Satellite Symposium on 26th September 2020

Portable station for QO-100 based on the modules of AMSAT-DL by Matthias DD1US.

A

The next presentation I will give myself- I will show you a portable station for q100 assembled from uh components from the amsa dl shop, so the dun converter up converter the modified lnb, and this will give us about. Therefore it will take about 45 minutes. So we should be on time, hopefully to then also be able to have.

B

A

Our lunch, um this show this block diagram shows uh the principle of the whole transverter.

A

um If you we have a 10 gigahertz lnb, like everybody, is using the mzl down converter with the integrated gps module and an up converter to generate the transmit signal.

A

Externally there is a gps antenna, module very simple antenna, active gps patch antenna, and we can also connect the 1.3 inch oled display to it from the lmb. We get the two downlink signals from the wideband transponder and the narrowband transponder wideband transponder, being horizontally polarized.

A

It needs 18, volt volt, provided by the down converter and what we also do. We provide a 28 megahertz reference frequency to the modified lnb generated in the down converter module. The narrowband transponder is vertically polarized and we supply 14 volt to switch the right polarization.

A

The down converter converts this signal down and then number one provides a wideband output at 1130 megahertz, where you can connect the atv receiver. It also provides 10 megahertz reference output and, in my case, I'll been using that for locking the icom ic 9700 to it and the receive.

A

If of the narrowband transponder, is chosen to be 145 megahertz the down converter, module can be per, can be changed to different higher frequencies. I have chosen a downlink on two meter and uplink on 70 centimeter, because you will never have your harmonics in the tx falling into the receive path. So.

B

A

Centimeters uh up link in up converted by the up converter to a 2.4 gigahertz uh signal going to the patch antenna. uh The output power, normal output power is about 3 watts, 2.8 watts. The whole setup is running with dc voltage between 9 and 15 volts, and we have some auxiliary ports like the ptt input and communication port output, where we can monitor the parameters of the up and down converter I'll. Come to that later.

A

If we look on how this hardware looks like the same block diagram now with the components, the lnb from amsat is a modified opticum ltp of 04h so modified, so that it gets the reference frequency from externally over the wideband output, we use the amstrad dl down converter uh and the up converter.

A

The uh feed I've chosen is a 40 feet, patch of the year, with a patch antenna for transmit and a circular waveguide for the uh receiving on tangible hertz uh with a went on rocket because I'm using an offset dish and for offset dish with higher f2d. It makes sense to add a lens to focus your beam and optimize. The radiation pattern of your feet into a offset dish with an f2d a higher than 0.4.

A

The uh assembled module looks like this. I put it in a uh in a box which is actually something I found in my drawers. You see the oled display in the front and uh yeah. That's, essentially, all the modules are in one of this. In one of the such a box, the frequency scheme, the precise frequency scheme, is shown here on this slide.

A

The wideband output from the lnb when it's operating from 24 megahertz reference frequency uh is 1132.5 megahertz. The down converter is really routing this signal out again to the wideband transponder output, so that you can connect your um 80 atv receiver, I'm using a mini tuner directly to this, the narrowband transponder output is at 1129.5, and, as I mentioned, this is down converted to two meter: gps input, 1500, the reference frequency output and, of course, the transmit output. The down converter with the gps module is also providing the reference frequency to the up converter.

A

So you have a small interconnection and this 40 megahertz signal is used by the up converter to precisely up convert the 70 centimeter. If to the 2.4 gigahertz signal for the for the uplink.

B

A

Is gps locked and in the down conversion, I've actually made some small modification or add-ons to the original set, I'm using a splitter to split the two meter down converted output, either directly go to an sdr, or before I go to my ic 9700 I've added a 30 db attenuator.

A

This is number one. The the gain of the lnb and the whole down conversion scheme is pretty high higher than really a normal radio needs. So down. Attenuation here does not really degrade your receiver performance because you have so much gain in front and if I'm unintentionally, transmitting in the rx output, this attenuator is capable of handling 100 watts. So I've tested it. You can never damage your down converter, even if you are making a mistake in the up conversion scheme.

A

Similarly, we have two inputs. One is a tx input with a low input power uh about -4 dbm is sufficient uh to go through a combiner into the up converter and generate this 2.8 watts, output power and for the ic9700.

A

I've also added here, a 30 db, attenuator additional limiter and a small accelerator for leveling the power to have the same input power here from the tx in low input and the high input nominal input power from the ic 9700 is one watts, but also.

B

A

I unintentionally transmit with 100 watts it's so absorbed in the attenuator and the rest is limited to 10 dbm by the limiter. So nothing can really happen uh when you're, for instance, in the field, and something goes wrong.

A

B

These are the the levels.

A

The nominal tx input levels I mentioned minus 4, dbm from the sdr input or 130 dbm from the ic 9700 attenuated limited, and finally, the input of the up converter is -5 dbm, which gives a 34.5 dbm output power.

A

The absolute tx input levels are really 100 watts on the ports which are connected to the trans to the transceiver uh at the uh tx in low input, you can uh have up to plus seven dbm five milliwatts, so you have a range of more than 10 db, go over the nominal range without creating any damage to the up converter.

A

If we look on the this is a measurement of the whole up converter and you see that the input is at 430 megahertz. I've used the tx in low port. This is the numbers you see in here. P p in is at the tx in low, and you see the output power here, the output power and the gain- and here you see the current consumption.

A

uh The 1db compression point of the whole chain is a little bit less than 2 watts. The saturated output power is 38, dbm um and uh there's also a table. uh You will see in the presentations which will be published if you are interested in some more of the details.

B

Interesting, the.

A

Efficiency of the whole transverter when you go close to saturation or in the higher output power range, is a little bit more than.

B

A

Power added efficiency.

A

So this is the front plate of the uh encasing where the transceiver is in. So you have the tx in low input port from the sdr about a quarter of a milliwatt is sufficient to drive the transverter. We have the tx in high the ptt input to key the transmitter.

A

Actually, you can also run the up converter all the time you can make a short here and run it. It only saves you a little bit of power, but it's running full duplex anyway. So if you don't want to to use the cable to your trans transceiver, you can just have here uh ground this and you will have the pdt on all the time the oled display is showing you here, for instance, the gps data, your qth locator the time and then also whether your transceiver is in a good shape.

A

So you see the output power of the. If the receive, if is in the two meter range, the lnb is supplied with 24 megahertz. We see 12, satellites unlocked and the precise latitude and longitude information. The communication output is a serial output, where you can show various operating parameters in a remote display. uh You, you will also. I don't know who is a member of amsterdam, but if you have seen the latest journal, we also have some information about how to use this com output, port, for instance, by a web server.

A

And then you can monitor your output power, various conditions, including the gps information we have on off switch. We have the power input 9 to 15 volts and the narrowband. I have output here. Actually on this picture, there is one uh connector missing, which is the uh the narrowband. I have output for the sdr, which I added later so I missed that on that picture. On the back side of the transverter, we see the white band input where we get the signal from the lnb at 1132, ish megahertz.

A

We see the uh wideband if output, so that's internally, routed through here, you can connect your mini tuner or whatever you prefer to uh receive the wideband signals. We have the narrowband input, also coming from the lb the gps antenna input, uh including the phantom feed, um the 10 megahertz reference output, which I'm using, for instance, for uh locking my ic 9700 to the transverter.

A

And this is the output for the transmitter going to the protein.

A

B

A

Picture the the encasing I had on hand has a large heat sink and all the components you will see the inside a little bit later are mounted on this heatsink, though there is no need for a fan with the efficiency. We have it's fully sufficient. Also, if you have it in the sun to run it without any active cooling.

A

This is how I mounted the transporter on my dish. I've mounted the arm for the feet upside down, you'll, see some details later, and so the cable from the output of the up converter to the feed is only about 40, centimeters, so very little losses, and so it's quite convenient to have it there yeah. This is the bottom part, and now we look inside you see here is the up converter part, which goes to the antenna port for the for the putty. This is the down converter part.

A

uh Here you see the attenuators. I show you some details later power, splitter limiter and then the front with the with the with the display and the user interface same picture, the other side, I'm using mostly a semi-rigid, cable or semi-flex cables because of the nice shielding or uh if I use flexible, cable, double sheet that cables are uh recommended.

A

uh Here you see the how I mounted the the up converter to the heatsink, uh I'm using a copper spreader, so a copper plate under under the uh up converter between the pc board of the up converter and the copper spreader. There is a thin layer of thermal conductive material which is flexible, but it brings all the heat from the pc board or most of the heat from the pc board, down to the the copper spreader, and so the converter stays pretty cool.

A

B

Down converter.

A

Is also mounted directly onto the heatsink, it's not absolutely necessary to mount the up and down converter into a shielded in casing, but I prefer this to make sure there is no un unwanted intercoupling or something so. I've put everything in shielded boxes, even though there is the metal encasing outside, of course, also shielding the whole setup.

A

There's a picture with the with the two boards open you see in the down converter, also, the gps module which is plugged on and the reference frequency output. There is a second reference frequency output, which is unused but terminated with a 50, ohm, resistor and- and here is the up converter board with the uh power management dc dc converters.

A

Here you see left is the input some filters drivers and these are the final stages for the power amplifier with 90 degree, hybrid shifters, which makes the pa also quite rugged with respect to a mismatch.

B

A

The antenna port because of this 90 degree hybrids, if there's a reflection, it gets absorbed in those resistors, the two tcx os on the gps board, as well as on the down converter board. I've- it's not shown here, but I have put additional foam inside before I put the lid on so this uh insulates these tcxo.

A

In addition to make it very thermal stable, uh it's uh it's no big deal, but I recommend to do this and to make sure that the tco drift is minimum. You know the short term. Variations are determined by the tcxo itself. The frequency variations. The long term is locked by the gps. The gps loop from the gps into the ocx tcxo by the pll is very slow, so it takes several seconds to lock and therefore, short term variation would be still visible on your output signal, or you can see on your receive signal.

A

So some thermal insulation is not mandatory, but it helps this. Has the 30 db power attenuators, which I built? I had them still on hand, and I used some surplus.

A

Teflon, pc board cut it and it's just 50 ohm input, output, traces and those are used, as I mentioned at the I have output of the receiver and the tx input uh from the transceiver, uh so that I cannot harm uh accidentally. The up and down converter, um the 30 db. Insertion loss is pretty precise and 270 centimeter and also the input return loss is very high. So this also helps you, because your transceiver will always see a perfect output match, so no problems can arise by mismatch of the transceiver.

A

This is the rf limiter I've been using. I also had this still in my drawers. This limits the input signal to plus tbm 10 dbm, so the input signals first attenuated by 30 db by the bigger attenuators and then the rest is limited uh power limited by this kind of diode limiter.

A

uh It's suitable for frequency range up to three gigahertz, though uh I operated at the 70 centimeter band insertion loss is pretty low, and once you exceed a certain level, uh then you see how the limiting the clipping of the signal is happening.

A

Of course, then, you also see some harmonics, but you, if you operate at a nominal input power of 0 dbm, the harmonics are below 60 db under the carrier and only if you increase it into the unwanted range which is not nominal, then you can see that it limits at about 9 dbm, and so it's pretty close to the spec.

A

The power splitter is a standard mini service power. Splitter. You can use different ones. This one is pretty small and I have built I've put two of them in the box, one to split the receive signal and feed it number one to an sdr and simultaneously to the transceiver, and the same is true for the transmit path.

A

Where I combine the input signal from an sdr and the transceiver to the input of the up converter, the insertion loss at 2, meter and 70 centimeters are measured also to be very low about 0.3 db for no issues there as you've seen. I've also put the oled display into the box. It's nicely supported by the firmware in the down converter.

A

There is an I square c interface and I can recommend this 3d printed frame. It makes it very simple to uh to mount this display onto the box. There's two pieces: you put the oled display into this bigger piece, and then you put the second part on the back and then you can screw it to the front plate of your up converter or transverter.

A

The design is by torsten, go down, he does alimony and if you want to get it printed for a little money, alfred cutler delta, lima, 3, mic x-ray is providing some printing service. You can.

B

Find the data also.

A

Or publicly the printing data, the body feed I modified a little bit and because I wanted to put it in a nice encasing to shield it against any weather influences the optical lnb.

A

Therefore I had to modify, I don't use the original ports for narrowband and wideband slash vertical horizontal output, but I put the thin coaxial cables inside because my my tube, which I'm using, has a diameter which doesn't allow to mount the connectors here, but it's very simple, put off the lid and you can connect such thin cables here on the cable just make sure it has good shielding.

A

The insertion loss really doesn't matter, because we have so much gain in the down converter of in the lmd that, uh even if you lose here on a short, cable one or two dbs, it doesn't really matter. We have, I think, more than 60 bb of gain here. You see the the putty feet with the the lens mounted. This ring is just to to shift the whole setup into the tube I'll. Show you some pictures later. You can see here an adapter from the waveguide to the input of the lnb.

A

A friend of mine has a cheat machine that it's made from brass and it's soldered onto the the copper wave guide, circular waveguide and then it's it has a taper inside, so uh it makes a transition transition from the slightly larger diameter of the waveguide of the putty feet to the thinner diameter of the lnb. So there's a taper and this this brass piece goes into this into the waveguide of the lnb.

A

It's then screwed down and firmly attached and yeah. It works pretty well here you see some pictures how the putty feet is in mounted into this standard, hd pipe, and I can really recommend the went on rocket lnb lens. Those lmds are very cheap. I think five or six euros just by the whole lmb. It's uh it's a dro.

B

A

Lnb so not really recommended for use here, especially on narrowband transponder, but I just used the the uh the lens of it, which are two pieces and glued it here. On top of the the front of the putting feet for.

B

Portable operation, typically, I leave it open.

A

But for permanent, I have also a teflon cover, it's a teflon point with a ring and it can be plugged onto the the tube the tube is mounted so that the opening is at the lower part. So no water can ingress. On the back. You see the outputs, the tx input and the two outputs for the down converters.

A

This is shown before I sealed it. Typically, I use a spinner plus 2000 to seal the connectors, and that makes it waterproof and inside you see the connection cables, which are then plugged into these cables. You've seen coming out of the lmb respectively. Here is an end connection going into the transmit port of the body.

A

The putty feet uh shows a very nice match. The input return loss is uh about 124 db. uh The whisper is about 1.14, so pretty nice match. You can also see here. This resonance is actually the effect of the booty, where we have a longer side here and the shorter side here, and this really generates the circular polarization, because we have a rational resonance slightly above the 2.4 gigahertz and slightly sort of slightly below and slightly above and at 2.4 gigahertz.

A

Those two resonances combine and you get the right phase shift to get the circular polarization.

A

This is the setup now uh in my backyard, I'm using a 60 centimeter offset dish from cutline and you can see the arm for the feet is mounted upside down, so there was no water coming in and also it. The transverse is mounted here on the back. It's actually also giving a pretty good balance of the whole setup, I'm using a battery to be for the portable operation with the small solar cells, which is buffering it and an ic 9700 it.

A

I started the using uh sdr from the beginning on qr100, but I have to say it's really fun also operating outside and without the need of the pc and just use the ic 9700. It's really fun.

A

um The you can see here on this picture, the transfer mounted on the arm. You can see here a small bracket with the gps patch antenna mounted on top of it and yeah, so there's actually no interference because the main beam is going out here. I haven't seen any problems with the gps antenna being influenced by the transmit signal of the converter, the nice thing about this cutline dish.

A

Actually, I found it on the scrap yard here and the local scrap yard cleaned it up a little bit and it has here four screws which you just loosen, and then you can see it here in more detail and then you just can easily remove the uh the dish from the from the mount and for storage and transportation.

A

Also, I have used one of my tripods from my telescopes and just made an adapter and also just losing three screws and easily. The whole thing is disassembled.

A

um This is a picture of the received signal uh using sdr console. uh You can see the beacon signals here, the psk beacon here and actually you can see even the signal mario mentioned the leakage of the blue toe very slightly here. So the setup with the 60 centimeter dish is amazingly uh sensitive. You don't really see the role of the transponder in terms of the transponder noise, so that's a little bit low, maybe half a db you can see, but also the uplink signal is about.

A

My uplink signal is about 60p below the beacon level, which is perfectly fine to make a good sideband qsos. So, yes, the 60 centimeter dish, I I believe we shouldn't go look below because you should always have a sensitive setup, but it's perfectly okay for using it for portable operation for datv, I'm using a mini tuner.

A

This one is actually from batc and it's connected on the back of the down converter. You've seen there is an output to the to the mini tuner, so I can actually also watch um while making sideband contacts. At the same time with the pc and the mini tuner watch the uh the atv downlink it's at the edge, I would say, uh because the dish is pretty small, but I show you some picture um you can you can watch d80 with it if the uplink signals are strong enough, um so.

B

A

uh This is the beacon, uh the datv beacon uh which we are transmitting from the ground station. You can see uh the 1.5 mega symbol per second sigma qpsk mer here was 6.1 db, so the minimum for receiving it is 4.7. So, with this setup I have a margin of 1.4 db, and here are some examples of some users.

A

This is uh oe 6k, gkd, transmitting with 500 kilo, samples and mer 4.5. You see the margin is very low, 0.5 db, so uh if, if some clouds are coming up or so you will always already lose the reception. So again, the 60 centimeter dish is really only recommended for portable operation. When we go to lower sample rates, the margin gets higher.

A

Here you see a signal from iw1 on the f at the six, any rf6 and the margin of 2 db and going lower or at similar margin, hb9 dug with 250 kilo, samples of 8psk signal and uh even 125 kilo samples from 0.5 afb um was received with that. So to simplify a little bit the setup I decided to to do something which we actually have done. Amsa dl has done.

A

Similarly, in the setup in in antarctica means reducing the cabling between the transporter and the transceiver, and I modified two uh triplexers because they have uh really pl connectors and uh I replaced it by end connectors, but essentially you can route them over. The tripod try uh triplexer the received signal on two meter: the transmit signal on 70 centimeter and the 10 megahertz reference frequency from the transverter to the transceiver. So I run only one coaxial cable here to the transceiver, and that makes the whole setup uh uh very easy um here.

A

You, you see the see the three signals: the two meter: narrowband output, the transmit input and the 10 megahertz reference from the uh transceiver from the transporter going through the triplexer into one cable and uh on in front of the ic9700 same thing happens. We get the signals here from the transcoder and split it up again into those three signals.

A

For portable operations, I wanted to have a simple way to transport it. So I built a wooden box from uh light poplar, plywood and uh outside you can easily. I can easily attach the parabolic dish with the two screws.

A

As I mentioned very simple, there are the four holes, there's oblong holes and you can hang in and attach and firmly attach, the the dish to the to the wooden box and inside the box. You can see that the whole setup of the uh mount on the tripod, uh including the transporter, the mini tuner and the feed, is all assembled.

A

So I only need to take this out, put it on the tripod and then hang in the dish and.

A

Screw tight the the four screws for for the um for the dish on the arm and uh less than 10 minutes. You are ready to go uh in the box. There is also space here for the ic 9700, so the whole setup can be easily stored and transported.

A

You can get the down converter, the up converter, which is has a maximum output power, 6 watt and the modified lnb on the amzr shop, and I would like to give a special thanks to stefan delta fox 8 golf alpha, charlie and kurt delta. Julia zero, alpha. Bravo, radio for developing this excellent transverter and there sometime soon. We will also have a new end casing for the up and down converter.

A

So if you are a little bit shy on doing the mechanical work, integrating the modules into a in casing, we will offer in the amsterdam shop already made in casing with engraved front panel and all the the holes are already in. Even the patch cables are included, so that will make life much easier for the users, and I would like to thank you very much for your attention and uh let me check on the transponder and also on the youtube whether there are any questions.

B

uh Yes, matthias, maybe I can step in because there's one question on the youtube channel that was about your equipment if it's all waterproof or is it workable for continuous work outside from h g 5, a ap? Maybe you can answer that question.

A

Okay, yeah thank.

B

A

Very much for the question. uh Actually, uh the the the dish itself. The feed itself is waterproof. uh I was running this. uh I'm running similar fields also on my permanent setup, the transfer box itself, if there's a little bit of water coming on, it's no problem, but it's not completely watertight.

A

So I'm not I'm not running the setup in the rain. Actually, I have a rundown and there there's a little bit of a glass over. So I put it typically there. If there was some rain, I just put a plastic bag on top of it. Then you can still use it because I, I assume you're not sitting with your transceiver in the rain and there's only one coaxial cable needed between the transverter and the transceiver and the the length actually doesn't matter.

A

You can easily run also 20 meters and if you put a plastic back just on top of the of the transverter, then you are perfectly fine.

A

Okay, uh let me check.

B

Yeah: okay! Well, no! No! More questions on the youtube channel! Nothing on the white ben transponder channel! So yeah back to you.

A

Good, so thank you uh florian, uh so we are well in time and actually it's always better to have a little bit earlier, the lunch break. um If there are no more questions and uh oh there there's a question here: uh how much current uh draw of the whole systems. uh Let me go back on the presentation.

A

A

Mario, can you go on this slide.

B

Yeah, just a second, I need to reopen the presentation because I closed.

A

B

Which slide do you need now.

A

uh It's the slide where you see the the measurement of the output power versus input power and also the current assumption is mentioned. There.

B

Okay, I'll look for that.

B

So it should be.

A

There's a graph and there's a.

B

Table this one yeah.

A

Here you go, you see, this is the. This is a total current consumption without the ic 9700, so it's up and down converter full duplex, so at 2.5 watts, output, power. uh Sorry, this is at a 6 watt output power at 2.4 or say 2 watts to 3 watts, output power. Current consumption is roughly 1.3 amps and then on top comes your transceiver.

A

uh The ic 9700 is a little bit power hungry because of the display, and so, if you use uh either the ic, 202, 402 or maybe 857, then the power consumption will be lower but of the transporter with the gps and the uh the lnb is included. All this included. It's about 1.3 amps, at nominal output power.

A

Okay, I think there is no more.

A

A