Idea Box: A Small Solar Lighting System Etc. for the Bedroom.

 Overview:

Using some GEL batteries for providing light in the bedroom. Using small panels mounted to the "top window panes", and a simple charge controller, e.g. the 10A model I already have. Tests of small solar panels will have to be made to see if they can provide sufficient power for the night light, as well as power for MP3 player(s) and amplifier(s), so some audio (e.g. audio books) can be played in there. If necessary, an externally mounted solar panel can be used, but a fully indoor system is preferred.

If this works a similar system can be used in the living room. Both rooms have windows facing South, so it might be possible.

A bit of testing and design:

All this should be tested, (and possibly used) until a more permanent system can be made for solar powering more of the house, e.g. a solar powered audio player system. 

A video player system will require more power, but this can be a start before more solar (entertainment) becomes available in the house.

Bedroom system:

Here is an idea for a small solar power system for the bedroom. As you can imagine, the power requirements for bedroom lighting are not very large, so I would like to add a low power "entertainment system", just for audio, some very low level "orientation lighting" with short LED strips, a "reading light", and a tiny audio system with one of my MP3 players, so I can listen to audio books when resting there, and a charger for the mobile devices, such as phone, tablets and e-readers. I suspect that I can keep the daily energy consumption down to some 10s of Wh, so I need to make myself a budget. 

First I will have to test the energy consumption of the different devices I have, then calculate the needed overhead of power, e.g. make an estimate of the number of sun-less days I need to have energy storage for.

I finally located some small panels I have. They are so-called 20W ones. I need to test them to see how it works in full sunlight (open circuit voltage and short circuit current test), and how they they work behind my windows I will try to make the system with some of those. I have 9 of them, so I should get sufficient power for some low light and some audio in the bedroom, probably using 3 or 4 of them. Even if they are only 10 - 15W the system should work. An effective 40W will likely be sufficient for the bedroom system.

Somewhere I should have a box of single cells and very small panels that I should test and see if I can get sufficient power out of them for similar systems

For similar systems I might also try to salvage some small panels from worn-out (discarded) solar-power-packs as well.

If I consider the idle current draw for the charge controller too high, I have to make a simple one myself, or a switching circuit for disconnecting it when there is no sunlight. 

If I get satisfied with this system I may make other low power systems for other uses, e.g. a weather station with remote sensing and rechargeable batteries as power supply.

Let this be the first test ...

New Antenna Experiment: 30m Wire.

 Today I made the initial test of the 30m long antenna wire I had lying around. I located a low power (probably absolutely max power 100W) 9:1 UN-UN.

I found a free cable end at the end of the out-house, and strung the wire from there to the low end of the garden. Both ends are only about 2m above ground, and the centre is sagging, so it is only about one meter above ground. There is a lot of room for improvements. The centre should be mounted near the centre of the dipole, i.e. about 5 - 6m above ground, and the end(s) should be higher up as well.

This antenna is right now connected to the IC-705 with about 15m RG-58 cable. Not the best in the world, but for the low frequencies it will work. Surprising that the OZ7IGY beacon is clearly audible on 2m and 70cm, despite the low height. 

The dipole cannot operate on 30m, so the 30m band was tested. A bit of a surprise, a QSO with a French station was easy, even running the 5W from the IC-705.

For now the wire antenna is connected to the '705, and some improvements are in my plans:

- mounting the antenna higher up

- adding some "radials", a 50m long piece, and a 10m long one, to see if the 160m band can be reached with a decent SWR. Right now the SWR is a bit up-and-down across the HF bands, starting being low-ish around 3.5MHz.

- adding a common mode choke at the feed point, so I can avoid RF running into the shack (and some of the noise being picked up on the outside of the cable).

If the weather permits, some of this will happen tomorrow, as well as weather proofing the setup.

The dipole is now connected to the IC-7300, and can be used on 4-6-10-12-15-17-20-40-80m, using the built-in tuner on some bands. At the moment the '7300 has been set to 5W out on the HF bands, but there is, of course some reserve if I *really* want to work a station - new country or the like.

I am expecting some packages tomorrow, so I can start improving the solar power setup. I expect to add the IC-7300 as one more load for the solar power setup, so in essence the "mainly QRP" setup will running on solar only.

Spectrum Analyzer Extender Using the HB100 Module as Down Converter.

Tonight I made a test of using the HB100 module as a down converter, so I should be able to "see" 10GHz band signals on my (low-cost) Tiny SA spectrum analyzer.

I have a few of the modules, so here goes:

With a previous test I had used a LNB with a more expensive spectrum analyzer I had access to. I tuned some HB100 modules to different frequencies, so I had some simple signal sources on frequencies from 10300 up to 10500MHz in 25MHz steps. I also made one for 10368MHz (narrow band) and for 10489MHz (QO100 segment).

Today I wanted to test how the HB100 module did as a simple dowm converter. Because it has been used with (broadcast) FM band receivers I am aware that it can be used as a general down converter, and sure enough, using a 10450MHz HB100 and a 10375MHz module, connecting the spectrum analyzer to the IF output of the module produced a 75MHz IF output. It does work as I expected.

However, I do not know the RF or IF) bandwidth of the module, so I have not checked that.

The base bandwidth of the Tiny SA is 350MHz, so I tested with a 10300 module and a 10600 module, and got a nice 300MHz signal. Using the modules is a bit tricky because the apparent output varies a lot when tuning.

Using a 10600MHz module should make "seeing" 10300 - 10900MHz with a small gap around 10600 (zero IF). Not too bad for a $5 module. For the putpose I also made a 10500MHz module (10200 - 10800MHz coverage) a 10300MHz module can be added for coverage all the way down to the 10000MHz band edge (10000 - 10600MHz)

I am well aware that I do not have any image rejection, but as long as I can calculate expected frequencies I should be able to estimate the spectrum of an oscillator or a transmitter.

The Tiny SA has a base bandwidth of 350MHz (LOW input), but also has an extended coverage up to 960MHz, so it should be possible to see more than 1800MHz with a single module. The question is how much IF bandwidth the module can provide. 

SM6WHY estimates on his blog that the IF bandwidth of the HB100 might be up to 2GHz. I have my doubts, but if that is the case I might try using my Chinese 35 - 4400MHz (primitive) spectrum analyzer which uses direct conversion to sweep the band. If I recall correctly, only 350MHz can be displayed at a time, but the 10500MHz version then might be able to cover 8500 - 12500MHz with a small gap around 10500.

Even if this is far from calibrated, it is much better than not being able to see anything.

For the initial test I just used the modules lying on the desk, with the antennas there. I do think that removing/disconnecting the antenna(s) and adding connectors, and put the module in a stable casing will improve the set-up considerably, both with respect to stability and reliability.

What do you think? a spectrum analyzer extender to the 10GHz band for about $5? Not bad. 

Week End Activity, P.3: Loop on Ground Receive Antenna Experiment.

 The loop antenna adventure continues.

This time I revised the Loop on Ground (LoG) setup.

Some time ago I tried out a LoG made with field telephone cable. This cable is mostly made of steel wires, but with a few strands of tinned copper wire, in a 4x5m configuration. Probably not the best material for antennas, and the results were disappointing, and the experiment was halted. Now it continues.

After cutting the grass (first time this year, so it took some effort) I found some thin wire to lay down. It may be replaced with weatherproof wire later, but I got to test the system, this time the wire is a bit longer, the configuration is about 5x8m, so the highest band expected to work properly is 30m. I use pegs to hold down the wire, the type used to hold wires for robotic lawn mowers.

The box with the transformer had to be repaired, too, one of the transformer wires had disconnected since I last made the experiment.

I am testing with the IC-7600. Here are the first test results:

Initially the noise level all over the bands was poor, but winding part of the cable a round a ferrite rod near the radio improved that. A better common mode choke is desirable. Now I need even more ferrite (toroids and other stuff) for reducing RFI all over the house.

MW/LW sounds quite noisy and with low S/N reception. Not as good as the small NCPL (w/amplifier at the radio), and certainly not as good as the Mini-Whip.

160m sounds OK-ish with no preamp, not spectacular

80m sounds good, signals weaker than on the low hanging dipole, but noise lower, too. Almost equal, but I suspect that the 

60m sounds good, not spectacular, looks like it is a bit noisier than the dipole (using Shannon Volmet and FT8 as test signals), but then again, the dipole is not resonant on 60m.

40m weaker than the dipole, but sounds quite good. Comparable S/N.

30m looks quite sensitive, no resonant antenna to compare with yet, but it sounds like a decent receive antenna

20m: Looks like S/N is worse than the R6000. No surprise, as the Loop on Ground is too large for 20m

I suspect that the best band for this antenna will be 80m. 40/60/160 are probably OK with a better set of common mode chokes at antenna and radio.

On all the bands the noise floor of the receiver increased when the antenna was connected, so the IC-7600 receiver is sufficiently sensitive on all the bands I intend to use it for. It should also prove a decent receive antenna for use from 1.6 - 12MHz. I think I shall keep it and probably replace the wire, then get it closer to the ground, maybe a few cm under ground level. With some weatherproofing this should prove an interesting low band receive antenna in the winter season.

Amplified RX Loop Test and a Little Outdoor Antenna Work.

 This week end I have been active with antenna work.

Small Receiving Loop.

The first was a test using a low cost Chinese amplifier for the NCPL (loop).

The amplifier is actually "overkill", stated gain/bandwidth is 32dB/1-2000MHz. Not surprising, the gain is too high, both attenuators are in action on the FRG-100 receiver, and the base noise level (not interference), especially on 5-10MHz, is still very high.

Considering that the antenna is till tested indoors in the noise field I would expect things to improve when the antenna (properly weather proofed) is placed outdoors, but there is still one problem. The high gain causes intermodulation, maybe also cross modulation. I have not tested this, but in addition it is possible that the amplifier is oscillating in the UHF range. 

Which signals cause the intermod etc? I suspect it can be the MW broadcast band, but given the bandwith/gain of the amplifier it could be FM broadcast stations, too.

As I suspected this type of amplifier is simply unsuitable for such low frequencies, but I had to test it.

A simple 2 transistor with negative feedback is in my thoughts, along with a pre-selector. N1KPR has published a simple design that could be made on simple perf-board. 

Outdoor antennas.

The weather was pleasantly warm today, so a little outdoor antenna work was done. Since I do it all alone things may take a bit longer.

First outdoor thing was removing the lowered 6m half wave vertical antenna. There was a bit of rust, so the WD-40 was in action. This antenna was mounted on a satellite dish mount on the lawn, so this is now freed for other antennas. In addition, the cable was freed as well, and put to good use.

The 5 band dipole (10-15-20-40-80) had been connected together with the 4m vertical (now partly lowered) with a HF/VHF diplexer, which this was removed. The dipole is now connected to the old 6m antenna cable. Testing from indoors, the dipole/cable system seems capable of operating on 6m and 4m, so for the moment the dipole is used for 4m, because the 6m reception is quite noisy. The performance is expected to be quite poor on 4 and 6m, but until a better solution is available this will have to do.

The (partly taken down) 4m antenna is now connected to the old cable, running indoors, so a very limited 4m reception is possible, until another 4m(6/10/30m) antenna can be tested. At the moment only a transceiver capable of running a repeater is connected.

For now the 4m will be run on the IC-7300 with the dipole, and 6m on the IC-7600 with the V-2000 vertical.

It looks like the weather will be quite good tomorrow, too, so I may find time for more antenna work.

My "Home Made" Challenge.

I have been thinking of challenging myself with respect to (partly, at least) home made transmit and receive equipment used for making minimum one contact or received signal on as many bands, and in as many modes, as I can possibly do.

First my definition on "home made". it can  be a few different things, all involving some thinking or building activity, for example:

- use of equipment not designed for amateur radio, e.g. using a satellite TV LNB for receiving 10GHz amateur radio signals.

- use of modified (possibly surplus) equipment, e.g. using a HB-100 Doppler radar module for transmitting wideband FM or ATV on 10GHz, a home made (or modified) modulator is needed.

- using a kit I built/assembled (maybe modified) myself, e.g. the very simple Pixie transceiver kit.

- building transmitter and/or receiver circuits in non-kit form.

All of this can be arranged in stages, for example:

- building a transmitter and using an available receiver (kit or no kit).

- building a receiver (in addition) (kit or no kit).

- full transceiver (modified, built, kit or no kit).

Right now the status for the "home made" challenge is as follows, for the OZ9QV callsign:

80m: CW TRX, the single frequency - band modified - Pixie kit. - one QSO

60m: CW TRX, the single frequency - band modified - Pixie kit. - one QSO

40m: CW TRX, the single frequency -      unmodified - Pixie kit. - one QSO

This is a long term challenge that I intend to work on, slowly increasing the scope of bands, modes etc. Modes should include CW, Phone (DSB/SSB/AM/FM - DIGI-voice?), Digital modes (e.g. FT8).

Simple monitoring RXs should be included in the challenge, too.

This will involve using many kinds of home made equipment, all the way from simple CW TX,RX to SSB TX,RX.

More than enough projects to keep me busy!

Another part of the challenge is attempting to work 100 contacts, QRO or QRP with home made TX&RX, then 100 DXCC entities, just on a single band.

Challenges not including home made stuff could be 100 contacts or 100 DXCCs with QRP on as many bands as possible.

I could probably dream up other challenges, but let us see what I manage to get done. 

Small Update on the QO-100 Uplink.

 The uplink signal using the single patch antenna resulted in quite a weak signal on the satellite, There were even instances where a station simply continued calling CQ while I called them, I could easily hear my signal on the downlink, but it was not strong enough to get any attention.

While I am planning on improving the set-up with a bigger dish and with a helical feed antenna, I was browsing for QO-100 feed antennas, and came across this 4-patch feed which has circular polarization. I realized that I have a small WiFi antenna, a so-called 14dBi panel that I estimated having 4 patches phased together, a bit like the feed in the link, albeit this just with linear polarization.

I taped the panel to the dish, got it aligned, and sure enough, the signal is a few dB stronger than before.

Further, I had removed a 10dB attenuator between the 432MHz TX and the up-converter, and when I received a report on a spurious signal on the CW signal I tested with reduced power, and sure enough the distortion disappeared and the tone was clean again. The S/N was even better, now close to 10dB in SSB bandwidth, a quite comfortable level for receiving a CW signal.

Further, after some email exchanges with PA1GSJ, and some of my previous thoughts, I will be testing some more improvements on the uplink.

- a circular polarized feed antenna, such as a helical.

- replacing the low cost satellite cable with RG-6 may provide a sufficiently low loss to eliminate the "driver" Edup amplifier and the extra filter in the outdoor unit.

- a larger dish for the uplink is contemplated, such as a 100cm one.

- I do have a 80cm dish, and I might replace the 60cm receive dish with this one.

- a better reference oscillator (set) 10/25MHz is on the way, so I know better which frequencies I work on

- a second receive converter , so I can use my dual band 2m/70cm TRX in satellite mode (70cm for the uplink and 2m for the downlink), and having the TX and RX tracking.

This is quite a list, so I will take my time and slowly improve/optimize the satellite system.

Uses for the HB100 Doppler Radar Module 10GHz Experiments.

The HB100 module is intended for use as a Doppler radar motion sensor, e.g. for door openers. Could be used as a primitive speed meter, like the speeding detectors used by the traffic police.

The price of the module itself is somewhere around $3

After testing that the modules with the tuning screw could be tuned down to about 10300MHz without serious degradation of the signal, I can now see several uses of the module, some already described by others.

Here is preliminary list (other uses may be added):

1) simple 10GHz signal generator, using the module as it is, with its PCB patch antenna, tuned to a specific frequency. See also the previous post on this blog where I tested the usefulness myself.
A signal generator for 10GHz for $3.

2) Simple 10GHz WBFM (wideband FM) or FM-ATV TX, using the module as it is, but modulating the power supply. A relatively simple modulator/power supply on PCB (or experimental board) is needed. Some people have already tried this, and a Google search will reveal several ways to generate the modulation.
The modulator could probably be made for $5-10.

3) Simple RX down converter for WBFM and FM-ATV, using the module as it is, and adding a receiver at the IF port. Poor sensitivity, so very short range as the module is.
If used as receive converter only, the TX signal should be terminated in 50 ohm or similar in place of being connected to the TX patch antennas.
$3 and a bit of work.

4) Simple down converter for spectrum analyzer/frequency counter. Using the module as in (3), with the IF port connected to Analyzer/Counter.
$3

5) Very simple WBFM transceiver for *very short range* communication, using the module as is, with a modulator and an inexpensive 80-108MHz FM receiver, Chinese module, can be purchased as a simple kit for around $3, and a cheap audio amplifier, also an inexpensive Chinese module.
I estimate that the complete transceiver could be made for about $25, depending on the  external circuits used

5a) The very simple transceiver can, most likely, be enhanced by a low gain "preamplifier" between the IF output of the module and the FM receiver.

5b) Some experimentation with mounting the HB100 inside a "horn antenna", using the module's patch antennas as "illuminators".

5c) The simple TRX can, of course, be mounted in or near the focal plane of a dish antenna.

6) I have a defective HB100 (No oscillation, and high power consumption, most probably due to reversed polarity of the power supply). Experimentation should be done to see, if it can be used as an up converter with a local oscillator suited for narrow band transverters.
A simple test would be trying to insert a low level RF signal at the IF port of a functioning HB100, and check the resulting spectrum radiated from the RX patch.

6a) The mixer could also be used as an RX down converter mixer, in the receive chain of a NB transverter

It should be noted that  the very simple WBFM TRX, or the module used as a simple down converter, has poor RX sensitivity, due to the loss in the passive mixer.
However, some people have made QSOs up to 200km LOS (line of sight) when using parabolic dish antennas, interesting what can be done with just a few mW. True QRP with extremely simple and inexpensive equipment.
Some experimentation with a TV-LNB followed by a WBFM RX, would probably result in enhancing the sensitivity by 10dB or more.

I can see that the is room for experimentation, and I need to try out some of the above ideas.

If you can think of other uses for the HB100, feel free to comment.

Idea Box: Second Experiment

The most local beacon for me is OZ7IGY, about 30km away.
Now I am curious how little effort it takes to receive it.
The idea is starting to use a PLL LNB without a dish, just the built-in feed horn.
Because the beacon is beyond line-of-sight, the propagation will be tropospheric scatter, so the signals may be too weak to hear, but the experiment should be done. Next step would be a 15-20dBi horn antenna, then a small dish, 30cm or so.

It would be fun, however, if the beacon is audible with just the LNB, even if it is not constantly audible. This may be an opportunity to try the PI4 mode for beacon detection.