Topband: Signal source RF amplifier

[VE6WZ_Steve]

Thanks for the info George.
I have watched your video….very FB indeed.

Using the 74HC244 line driver/buffer as a PA is a great idea.  I had heard of this idea before, but never found a circuit.
Jim, WA9VEZ put me on to this design which gives good detail and output matching ideas.
https://circuitsalad.com/2015/07/23/1-watt-qrp-rf-amp-using-74ac240-or-74ac04-inverter/ <https://circuitsalad.com/2015/07/23/1-watt-qrp-rf-amp-using-74ac240-or-74ac04-inverter/>
It’s great to get detail from someone who has already built up the circuit and done the experimenting.
This will be a fun project for the next few weeks.

This fellow, Ray Ring has an amazing blog with a gold mine of circuit ideas and design.  He is bookmarked on my computer now!
https://circuitsalad.com/ <https://circuitsalad.com/>

73, de steve ve6wz


> On May 3, 2021, at 7:17 AM, GEORGE WALLNER <aa7jv at atlanticbb.net> wrote:
> 
> Hello Steve,
> 
> I have built exactly what you are looking for: a small 200 mW transmitter that can be attached to a drone (including battery).
> 
> For the "PA" stage a I used a 74HC244 buffer, with all the gates paralleled, feeding a resonant tank wound on a ferrite rod, which is also the antenna. The battery is a single 3.7 V 500 mAhr LiPO. My -30 dBi two element loaded loop array can "hear" it from about half a mile, far enough to do RX antenna pattern measurements.
> 
> See : https://www.youtube.com/watch?v=JMujut_5FdY <https://www.youtube.com/watch?v=JMujut_5FdY>
>  
> GL and 73,
> 
> George
> 
> AA7JV/C6AGU
> 
>  
>  
>  
>  
> On Sun, 2 May 2021 18:46:49 -0600
> 
> VE6WZ_Steve <ve6wz at shaw.ca> wrote:
> 
> For field testing, I’m looking for some ideas for a very small RF amplifier to boost the output from a HCMOS 1.843 MHz oscillator.
> 
> These oscillators will give me about 20 mW max, but I need a bit more since I plan to mount it on my small drone and will need a bit more range.
> 
> My drone can lift up 130 grams, so I’d like it to run on a 5v supply. (maybe a 9v battery with regulator or 3 AAA cells)
> 
>  
> I considered something like a Mini Circuits PHA-13ln 21 dB monolithic amp, but not sure thats such a good idea.
> 
> A 2N5109 base amp is a current pig and too heavy.
> 
>  
> Any ideas?
> 
>  
> 73, de steve ve6wz
> 
>  
>  
> _________________
> 
> Searchable Archives: http://www.contesting.com/_topband <http://www.contesting.com/_topband> - Topband Reflector
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