Single transistor Carrier wave Tx

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Shaun
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Joined: 15 Feb 2018, 21:49
Location: West Yorkshire

Single transistor Carrier wave Tx

Post by Shaun »

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
Rameco PCB.JPG
Plastic Case
Plastic case Tx.JPG
Die-cast case (plastic one initially used affected range)
Rameco Tx 2.JPG
Rameco Tx.JPG
Article
DSCF0205.JPG
DSCF0206.JPG
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
Last edited by Shaun on 04 Mar 2018, 11:04, edited 2 times in total.
Tobe
Posts: 712
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: Single transistor Carrier wave Tx

Post by Tobe »

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
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RON
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Location: Stokesley North Yorkshire

Re: Single transistor Carrier wave Tx

Post by RON »

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.
G0MBV Class A Radio Amateur, North Yorkshire
Tobe
Posts: 712
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: Single transistor Carrier wave Tx

Post by Tobe »

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
Cheers,

Tobe
Martin
Posts: 782
Joined: 16 Feb 2018, 14:11
Location: Warwickshire

Re: Single transistor Carrier wave Tx

Post by Martin »

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. :D
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PaulJ
Posts: 652
Joined: 16 Feb 2018, 19:01
Location: Ipswich, UK

Re: Single transistor Carrier wave Tx

Post by PaulJ »

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
jackdaw
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Joined: 16 Feb 2018, 20:30
Location: Wet and Windy North Wales

Re: Single transistor Carrier wave Tx

Post by jackdaw »

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.
Martin
Posts: 782
Joined: 16 Feb 2018, 14:11
Location: Warwickshire

Re: Single transistor Carrier wave Tx

Post by Martin »

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. :D
jackdaw
Posts: 165
Joined: 16 Feb 2018, 20:30
Location: Wet and Windy North Wales

Re: Single transistor Carrier wave Tx

Post by jackdaw »

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.
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PaulJ
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Joined: 16 Feb 2018, 19:01
Location: Ipswich, UK

Re: Single transistor Carrier wave Tx

Post by PaulJ »

Phil_G wrote: 04 Mar 2018, 13:49 Does hamology still happen? seems little point these days!
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? :roll:
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