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Author Topic: New solid state QRP rig  (Read 961 times)

Offline ve3lyx

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New solid state QRP rig
« on: October 15, 2015, 12:19:51 UTC »
With an admiring nod to Dave Ingram for the design. I built and am operating the Micronaut Transmitter. It is a good design I would say as it works very well. Considering its low parts count, I would give it an A+. It was the Mouser 40 build that drew my attention to this circuit so thanks for posting it. I used a 2N2905 transistor because I have about 100 of them. Floor sweeping from the old Nortel Plant in Belleville. A customer of mine gave them to  me probably 25 to 30 years ago. At first I used the old colour burst  crystal (almost 3580 is how I think of it) Unfortunately here anyway there is a station of some sort occupying that freq several nights a week now. However I had bought several crystals for transistor use many years ago and they were in my crystal parts drawer so I choose a 3560 rock yesterday and swapped the old TV freq out. I know, I am a tube guy but I like to keep my hand in. I also built a matching RX. Both rigs are mounted in a dollar store wooden file box. The TX is labeled out and the RX labeled in. Who would know?
I fire the tx up while I am refining the regen so if you hear a pipsqueak on 3560 listen close. It might be me.
don VE3LYX

Offline AK0B

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Re: New solid state QRP rig
« Reply #1 on: October 16, 2015, 16:35:25 UTC »
I love your custom key.  :)

How wide a frequency band do you tune when working  fixed frequency?

I know many now days with their fancy transceiver don't tune anywhere, just their own frequency.
I grew up in the days we would scan 25 kHz for a contact when we send out a CQ. Which helped my DXCC count in later years as I scan the band for contacts.

Even today I still scan 10 kHz unless I am running something like a PIXIE.  But most of my DIY transmitters are fixed frequency -- I use a separate receiver to tune in the other station. I notice a few of the tube transmitter types still also do that but not the many of the newer ones in the hobby.

Lately I have been playing with Pippin xmit circuits.  Simple transmitter with a NPN and PNP transistor. I have found many transistor pairs that cost less than a dime will yield a good watt output. Using color TV crystals found I can build one for under a dollar if I use resonant circuits in place of a LPF, and less than two bucks with a LPF output running 2 to 5 watts.  I have a DC receiver in work and thinking about a regen.

It is fun to DIY and see how the world responds to you weak signal CQs.

73, Stan AK0B
 


Offline ve3lyx

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Re: New solid state QRP rig
« Reply #2 on: October 16, 2015, 17:44:31 UTC »
I usually roll either side just in case there is someone nearby and maybe even unable to come to my freq. No reason why we cant still work. Thanks on the key. It surprises me how nice it is to use. I think my CW is best on it. I love the homebrew or homebuilt stuff. You can build it in the morning and be on air in the afternoon. Cost like you say is a couple of bucks if that even. I was going to do a DC rx but am struggling with it. I remember my last one and still have a few of the boards. I am a regen guy at heart. Probably because of the super performance they offer and the unbelievable simplicity. In fact last night I was on with my BE rig, a 5 watt single tube type and the 6sl7 Regen, a twinplex and was thinking how much better it works then any of my superhets. I have in my shacks  now 12  operational regens. Can almost build them in my sleep. Both tube and solid state types. There is something about the thrill of running a successful QSO on a completely homebrew station that I enjoy. It has raised my level of enjoyment of the hobby to a new level.
don VE3LYX