Antenna

Buy Bobcat Miner from the official website: https://www.bobcatminer.com

Buy RakWireless Antenna?

What’s the Bobcat Antenna Connector Type?

If you are not using the stock Antenna, make sure your are using the right connector. Especially when using cable connecting to an outdoor Antenna. Wrong connector will cause NO BEACONS & NO WITNESSES.

Bobcat & Rak is using RP SMA Female Connector (1).

You need a RP SMA Male adapter to connect to it.

You may also need to choose N type connector to connect to your Non-stock Antenna.

What’s the Antenna dBi should I choose?

This is very complex but I’ll try to explain a little bit. Is dBi larger the better? NO. Please see the image below.

It depends on where your Miner is located. If you are on the mountain and there are very few Miners nearby, you should choose a higher dBi Antenna to reach miners in the city. In this case, maybe a directional Antenna will be better to cover one side. If you are in a city where there are a lot of Miners nearby, you should choose a lower dBi Antenna because the witness RSSI quality is very important to your income. The Bobcat’s Antenna dBi is 4, it’s a good balance of distance and coverage. High dBi Antenna can talk further but RSSI quality is not good in many cases. You may see a lot of invalid witnesses even if it’s near your Miner. That is one of the reason that some miners have a lot of witnesses but income lower than expected. One of the Antenna I’ve tested only gets 0.01 level tokens each witness but it had witnesses every 5 minutes.

A very good witness can earn a lot. This image was before halvening. A good witness means the hotspot is playing an important role in the current PoC.
The fewer hotspots joined the current PoC, the better (That means good location, people can’t put a lot of hotspots at the same place).
The better RSSI, the better reward. Make sure it’s not below lower bound and not over upper bound. (That means height, the higher, the better signal).
Not about Antenna but the better network, the better reward. (That means no relay/firewall issues, after received the data, it can send the PoC receipt to the CG fastly without trying again and again, finally failed to send a receipt).

A weak witness only earn a bit.
A bad witness won’t earn anything due to below lower bound error (sometimes network error).
What will happen if my signal is too strong?

This is very serious. You will be punished. When the witness RSSI is too high, it’s possible that you are putting multiple Miners together and asserting fake addresses. In this case, it’s possible you loss the beacons or your scale becomes lower and lower. I’m not sure if it can be recovered but there’s a score to affect your income. Even your miner is working now, you will loss income with the upgrade of the blockchain.

It seems your scale will loss 0.01 every time you received 1 witness_rssi_too_high INVALID witness.

Should I use a Cable to connect to the Antenna?

It’s best to connect the antenna to your Miner without any cable. But because most of the Miners are indoor only, you will need a cable to connect to your outdoor Antenna. Keep in mind that the longer the cable you use, the more dBi loss. Below is a calculator to help you calculate it.

Parameters:
Line Type:
Line Length: Feet Meters
Frequency: MHz
Load SWR::1
Power In:Watts
Results:
Matched Loss:dB
SWR Loss:dB
Total Loss:dB
Power Out:Watts
Power Loss:%
How should I choose the Cable?

It depends on your Antenna dBi, the length of the Cable and the distribution of miners around you. To achieve the best SNR, you can choose a cable with lower loss for example GB58(thin), LRM400(thick). But keep in mind the best SNR doesn’t mean a good thing, a bad RSSI and SNR combination will cause your witness be invalid or very low HNT. Testing Antenna is difficult.
There are many factors. I’m tesing over 20 types of Antennas for now and will keep updating this page. To find the loss of your cable, please use the calculator above.


Then how should I choose the Antenna? I have tested several antennas but to be honest there were few differences, maybe this one is a little bit Cheaper? It seems location, height and low loss is way more important than Antenna. I’ll test more and update this.
Where should I locate it? Where the scale is higher. A higher geo location and Antenna outdoor. To Be Continued.

Antenna is broken?
About the TX Power

There’s a gateway config file in Miners defined the dBi gain and frequencies. These configurations will be used to calculate if a received radio is valid. If your Antenna doesn’t work well, it may send packets don’t meet the configuration. For example, maybe there will be a “no match of right hand value { error, bad_tx_power }” error. So before you switching to another Antenna, try the stock Antenna first to make sure your Miner works.

Is the Bobcat stock Antenna waterproof?

I think so, include the bottom if it’s only in the rain. Because the bottom part is just a magnet. But if you put it under the water, not sure if it works.

Buy Bobcat Miner from the official website: https://www.bobcatminer.com.

Buy RakWireless Antenna?

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