I built this Rameco a few years ago from an early RCM&E article. It was available as a kit but they published the full details of it in the mag. Works surprisingly well. Full range was achieved by plugging a piano wire extension piece into the loading coil.
Circuit on Veroboard
Plastic Case
Die-cast case (plastic one initially used affected range)
Article
I seem to remember Phil telling me there used to be a challenge among radio hams to see how far you could transmit a morse signal on a single transistor Tx.
Cheers,
Shaun
Single transistor Carrier wave Tx
- Shaun
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- Location: West Yorkshire
Single transistor Carrier wave Tx
Last edited by Shaun on 04 Mar 2018, 11:04, edited 2 times in total.
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- Location: Varberg or Stockholm, Sweden
Re: Single transistor Carrier wave Tx
The CW-QRP people's, low power radio amateurs, are able to cover the full earth with proper propagation with a few 100 mW or less! Personally I used to have regularly contacts with Europe with 0.5 watts on CW and 5 watts on SSB on 20 meters with a full length dipole as antenna.
Cheers,
Tobe
Tobe
- RON
- Site Admin
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- Location: Stokesley North Yorkshire
Re: Single transistor Carrier wave Tx
Didn’t know you were a radio amateur Tobe.
I used to work CW when I was right into playing radio.
Call sign G0MBV. My licsence is still valid and current.
Might of even worked you.
I can remember building my first ever qrp transmitter using just a BFY51 and a 3.58Mhz crystal powered by just a PP3 battery. First ever test I called CQ and amazed when a SP returned my call sign. For those who don’t know that’s a contact in Poland.
From what I remember, the transmitter was built on Veroboard and measured just 1 inch square. Single transistor. Antenna was simply a long wire.
Ron.
I used to work CW when I was right into playing radio.
Call sign G0MBV. My licsence is still valid and current.
Might of even worked you.
I can remember building my first ever qrp transmitter using just a BFY51 and a 3.58Mhz crystal powered by just a PP3 battery. First ever test I called CQ and amazed when a SP returned my call sign. For those who don’t know that’s a contact in Poland.
From what I remember, the transmitter was built on Veroboard and measured just 1 inch square. Single transistor. Antenna was simply a long wire.
Ron.
G0MBV Class A Radio Amateur, North Yorkshire
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- Posts: 712
- Joined: 16 Feb 2018, 06:19
- Location: Varberg or Stockholm, Sweden
Re: Single transistor Carrier wave Tx
Sure "ham" !
W4TDK & SM6YXK
The good thing when living in the US was that we were able to fly RC on 6-meters
Don't run much CW anymore, most SSB and PSK on 20-mtrs
W4TDK & SM6YXK
The good thing when living in the US was that we were able to fly RC on 6-meters
Don't run much CW anymore, most SSB and PSK on 20-mtrs
Cheers,
Tobe
Tobe
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- Location: Warwickshire
Re: Single transistor Carrier wave Tx
I'm G0WDU. I've operated QRP (3 watts) CW on 40 metres to Argentina on a half-size G5RV antenna pretty low to the ground. Of course, the guy at the other end was doing most of the work with a big directional beam antenna. 

- PaulJ
- Posts: 652
- Joined: 16 Feb 2018, 19:01
- Location: Ipswich, UK
Re: Single transistor Carrier wave Tx
I'm M0PWJ...... I only took the license so I could use it as a "Maritime Mobile" from my boat. I do have a rig out in my mancave but to be honest I got fed up with talking about other people's antennae and I haven't used it for ages.
Paul
Paul
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- Location: Wet and Windy North Wales
Re: Single transistor Carrier wave Tx
Don't think so, 'tinternet just about killed it. Last time I had a listen on 70cm, a good number of years back, I only got one mobile and a group of three having a brief chat and that was over a monitoring period of several months.
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- Joined: 16 Feb 2018, 14:11
- Location: Warwickshire
Re: Single transistor Carrier wave Tx
Yeah - I've not been active for years. I enjoyed building some rigs and trying out the various modes - slow scan TV, packet and so on... but I never got much enjoyment from operating once I'd got the stuff working. To me it always seemed like dialing a number at random on a phone and then asking the person who answered what their location was and what sort of phone they were using. 

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- Posts: 165
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- Location: Wet and Windy North Wales
Re: Single transistor Carrier wave Tx
Over recent years my wife has been to Thailand, Cambodia, Vietnam, Borneo(Orangutan rehabilitation center in the jungle), Kenya(Masi Mara game reserve) and Cuba. In all locations she Skyped me on her ipod and we had many video chats with a virtual tour for me of her location. Ham radio can't match that. The fun was in the making but its now like making a stone axe when you have a 50 cal machine gun available.
- PaulJ
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- Joined: 16 Feb 2018, 19:01
- Location: Ipswich, UK
Re: Single transistor Carrier wave Tx
I think there are are plenty of people still doing it........ Last time I tried, which was a couple of years ago, when 20mtrs opened up I could hardly get a word in edgeways . I now live in a bit of dip and surrounded by trees which is not ideal and I wanted to see if I could get anything at all. I rigged an inverted V antenna and got several contacts in Eastern Europe and also the USA...... It was really very busy! But as others have said, once you have done it, what's the point?
