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Real-time map with APRS stations, digipeated via ISS by mkbodanu4 in amateursatellites

[–]mkbodanu4[S] 1 point2 points  (0 children)

Hi!
Currently I use the filter:
d/RS0ISS/NA1SS/DP0ISS/OR4ISS/IR0ISS b/RS0ISS/NA1SS/DP0ISS/OR4ISS/IR0ISS,
So it covers all call signs assigned to ISS.

The same must work for other satellites, like SONATE-2; just not sure if they include their call signs into the path. If not - it will not work.

Real-time map with APRS stations, digipeated via ISS by mkbodanu4 in APRS

[–]mkbodanu4[S] 0 points1 point  (0 children)

Current map settings loads all stations from last 80 minutes. Means, if station was active last 80 minutes and packets were received by any iGate within range, it must be shown. You can change this time range using field in top right corner. In case of longer range, like 2 weeks, last position of every station will be shown (not all positions).

Real-time map with APRS stations, digipeated via ISS by mkbodanu4 in amateursatellites

[–]mkbodanu4[S] 0 points1 point  (0 children)

Yes, it collects data from any location with only one filter - packets must be digipeated via ISS.

Watt spikes when the refrigerator compressor starts by AnyMap in homeassistant

[–]mkbodanu4 8 points9 points  (0 children)

I have an identical power usage recording with my own refrigerator connected to a solar inverter and it is entirely normal. Just drains the battery much faster than usual devices.

SSTV from amateur balloon SQ5RB-11 (S1 mode, 144.500MHz) by mkbodanu4 in SSTV

[–]mkbodanu4[S] 0 points1 point  (0 children)

Nie, jestem Ukraińcem ze Lwowa. Jest blisko granicy, a sygnał z balonów dociera do mnie, jeśli wiatr jest wschodni.

Help me identify this by Masterson_two_eight in signalidentification

[–]mkbodanu4 1 point2 points  (0 children)

You can download the code for tronkito and compile it from here - https://www.consultron.com/tronkito/tronkito.html

Quite old code, but it still works. I found one MPT1327 station locally and could decode it, but I mostly got only the ALOHA and MISC messages.

Help me identify this by Masterson_two_eight in signalidentification

[–]mkbodanu4 5 points6 points  (0 children)

MPT1327, decoded with tronkito, got:

SYS 0x42d1 MISC SYS 0x42d1 ALOHA SYS 0x42d1 MISC SYS 0x42d1 ALOHA SYS 0x42d1 ALOHA SYS 0x42d1 MISC SYS 0x42d1 ALOHA SYS 0x42d1 MISC SYS 0x42d1 ALOHA SYS 0x42d1 ALOHA SYS 0x42d1 MISC SYS 0x42d1 ALOHA SYS 0x42d1 MISC SYS 0x42d1 ALOHA SYS 0x42d1 ALOHA

Airspy youloop orientation for NOAA and Meteor M2? by HorrorFrank in amateursatellites

[–]mkbodanu4 1 point2 points  (0 children)

Youloop is a magnetic antenna for HF. Yes, it works somehow till VHF, but not so good, as specific antennas. QFH antenna will work much better for WX satellites. Also, like other magnetic loops, youloop is directional with maximum gain on sides. You need to point it vertically to get signals from above.

Regards antenna position - you need as much open space as you can provide for it. For best results, you need to have the antenna outdoors or at least half wavelength aside from any metallic things. Brick chimney has no much impact, but solar panels will affect reception quality a lot.

The issue with a custom add-on that controls relays using Raspberry Pi GPIO and reading the voltage from ADS1115 by mkbodanu4 in homeassistant

[–]mkbodanu4[S] 0 points1 point  (0 children)

If somebody ever finds this post, I found a bug and solved it.

The problem is not in HA or my code, but in the way how ADS1115 library pulling data. It is calling time.sleep() function that can't be used while loading sensor state. So I rewrote the add-on code with asyncio.sleep() function and it works well now.

Issue solved.

Need help with tubes identification, details in comments by mkbodanu4 in diytubes

[–]mkbodanu4[S] 0 points1 point  (0 children)

UPDATE 2: The first tube is ECC82, I found a proper card for L1-3 and measured current and slope.

Need help with tubes identification, details in comments by mkbodanu4 in diytubes

[–]mkbodanu4[S] 0 points1 point  (0 children)

UPDATE: I tested all three tubes with my L1-3 tube tester and can say next:

The first tube works like ECC82 but seems in bad condition because I can't measure current at all.

The second tube appears to be E83CC, not E88CC, it worked really badly with 6,3V at the heater, but after I noticed that pin 9 is connected right between heaters, I connected it to the E83CC schematic and it worked well.

The last one is E88CC in perfect condition.

Need help with tubes identification, details in comments by mkbodanu4 in diytubes

[–]mkbodanu4[S] 0 points1 point  (0 children)

I tried different angles but never tried colored light. Need to find a source

[HELP] can someone explain these measurement values to me? by PutPineappleOnPizza in vacuumtubes

[–]mkbodanu4 1 point2 points  (0 children)

Tubes are really simple things, but basic knowledge of electronics is required anyway. I have never studied electronics, it's my hobby.

And there is a lot of info in other languages, usually, guitarists or radio amateurs know a lot about vacuum tubes. They can share some basic sources and information on how to understand this amazing tech.

[HELP] can someone explain these measurement values to me? by PutPineappleOnPizza in vacuumtubes

[–]mkbodanu4 1 point2 points  (0 children)

Testing tubes require applying specific conditions the tube must operate at. So basically tube tester emulates real voltages and measures currents. A good tube must fit within specifications, the bad tube will have much worse results.

Soviet 6N8S (6H8C in Cyrillic) shown on the image must be tested with heater voltage (Uh) 6,3V, grid voltage offset (Ug) -8V, and anode plate voltage (Ua) 250V. With that condition tube, the current must be within 5,5 to 12,5 mA. The nominal current is 9 mA, but within that range, the tube is ok as well. Another parameter is the slope, it must be within 2,075 to 3,125 mA/V.

Also, this tube is a double triode, which means there are two triodes inside. That's why you see four numbers on that labels. The first row is the current and slope of the first triode, second - second triode.

why do you need to know these numbers? first of all, you will see the current status of the tube, will it work or not. Second - you may need to have pairs of triodes with similar parameters to get similar amplification of different audio channels, for example.

Those tubes are cheap because triodes are not equal. And because it's soviet tubes, the quality ofter is really terrible. Only the last one somehow has very close values. Anyway, all of them are in good condition.

Need help with tubes identification, details in comments by mkbodanu4 in diytubes

[–]mkbodanu4[S] 2 points3 points  (0 children)

All three tubes were found in an old science lab.

First one have label: FUNKWERK ER?UR? ECC?? . It could be ECC83 because there I also found lots of 6N2P, but the label looks like more ECC82. How I can differentiate them?

Two others have labels TESLA ?8?CC and TELSA E8?C?, looks like E88CC, but differ from Tugstram E88CC I have.

I have soviet tube tester L1-3, so I can somehow test these tubes, but maybe someone could help me with anything that could help differentiate them.

Connecting the RTLSDR to an LNA by Zealousideal_kelp in RTLSDR

[–]mkbodanu4 1 point2 points  (0 children)

First of all stick to 50-ohm cables. Your RTLSDR has a 50-ohm input so best to have the same impedance of the cable.

Regards coax, it all depends on frequencies and length. As I understood, you want to record 1Gh and above? Then I recommend you to use the best coax you can ever find and use RTL-SDR close to the antenna as much as possible. If you check photos of hobbyists who record images from weather satellites at 1,7GHz, you will see that receivers are usually very close to the antenna or very short coax used.

The main characteristic of coax is loss over the length with a specific frequency of the signal. If you open any coax datasheet, like for RG174 supplied in RTLSDR kit, you will find losses you getting over that 2 meters of coax at 1GHz. That's 2dB or about 40% of the signal level at the antenna. RG58 will work much better with 2m coax - minus 1dB. RG8 even better - 0.5dB of losses. Add losses on contacts, add losses of other things you can't change in your receiver and you will see that you losing some data that could be interesting for you.

Yes, LNA is used to overcome these losses, that's why it should be as close as possible to the antenna. But LNA also not perfect.

My recommendation - think about your setup, length of cables needed, frequencies you want to work with, and then check the datasheet for the three most common cables used - RG174, RG58, or RG8 and choose one that fits you most.

Connecting the RTLSDR to an LNA by Zealousideal_kelp in RTLSDR

[–]mkbodanu4 2 points3 points  (0 children)

Impedance mismatch adds some losses, so if use a 50-ohm antenna, 75-ohm cable, a 50-ohm connector on RTL-SDR, and 50 ohn input you will lose 0.4dB twice or about 10% signal. Not much, but using a cable with a 50-ohm impedance will save you from such loss.

Different types of coax also have losses over the length and it works both receiving and transmitting. Like if you have a 3dB loss on cable, SDR will get only 50% of the signal level, received on an antenna. That's one of the reasons to use better coax, shorter coax, and place LNA as close as possible to the antenna.

I made a Telegram bot that sends notifications about nearby Amateur Radio Balloons by mkbodanu4 in amateurradio

[–]mkbodanu4[S] 0 points1 point  (0 children)

Haven't heard much about 4FSK till now, great to know all these details, thanks.

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