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Topic: Rf module upgrade (Read 2015 times) previous topic - next topic

Noah517

Aug 25, 2017, 04:47 am Last Edit: Aug 25, 2017, 04:54 am by Noah517
So I want to make a high altitude ballon. I have my ham license so I was planning to use the 433mhz band. I have some hc12s I would like to use for it. The hc12 gives of 100 miliwatts of power. I need at least 1 watt. Can I use a rf power amplifier to boost it to 3 watts? I found one on eBay for 20 dollars. If I can, I think that's better then buying a 100 dollar 1 watt rf module online.

Paul_KD7HB

So I want to make a high altitude ballon. I have my ham license so I was planning to use the 433mhz band. I have some hc12s I would like to use for it. The hc12 gives of 100 miliwatts of power. I need at least 1 watt. Can I use a rf power amplifier to boost it to 3 watts? I found one on eBay for 20 dollars. If I can, I think that's better then buying a 100 dollar 1 watt rf module online.
Since you have your ham license, you already know the different classes of RF amplifiers. The Ebay amp will have to be a LINEAR amplifier, not a class C amp. The amplifier has to maintain the modulation scheme of your hc12.

Paul

mauried

The HC12 is a transceiver.
While you can amplify the output with an amplifier, you still have to be able to receive and that means somehow bypassing the amplifier when the HC12 is receiving.
Amplifiers are not bi directional.

Noah517

Can you explain that more in depth? I know that class A, B, and AB are linear amplifiers. Which one should I use?

mauried

None.
To amplify a transceiver, you need a bi directional amplifier, and with a HC12 as it can switch from receive to transmit and back extremely quickly, you need one with hi speed internal switching.
This is not an easy task.
Id look at using a high gain antenna  instead, or look for a differant type of radio where the transmitter and the receiver are separate.


Paul_KD7HB

Rather than spend all your time trying to reinvent what has been done for years, Google :ham radio balloon transmitter" and see what works.

Paul

srnet

So I want to make a high altitude ballon. I have my ham license so I was planning to use the 433mhz band. I have some hc12s I would like to use for it. The hc12 gives of 100 miliwatts of power. I need at least 1 watt. Can I use a rf power amplifier to boost it to 3 watts? I found one on eBay for 20 dollars. If I can, I think that's better then buying a 100 dollar 1 watt rf module online.
You really cannot have done much research.

A 433Mhz LoRa module will give you around 300km of two way comms to a high altitude balloon using a mere 10mW. Which will polute the RF spectrum far less than blasting multiple watts everywhere.

There is a nation on one side of the Atlantic, the other side to me (UK), where HAMs assume the answer to comms problems is to use more power.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

jremington

#7
Sep 16, 2017, 03:56 am Last Edit: Sep 16, 2017, 03:56 am by jremington
In the U.S., most competent HAMs understand the importance of good, properly matched antennas.

The OP does not seem to be one of those, and needs to do quite a bit of reading.

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