Quote:
Originally Posted by Philips210
Hi.
I'd be keen to see if other members have successfully built the loop aerial amplifier.
It's quite a considerable effort building the amplifier and loop aerial but the results are worthwhile.
To date, I think that I'm the only person to successfully build the PCB version of the amplifier by David G4EBT. This thread has gone very quiet and I wonder if the OP has lost interest in this thread as he's normally keen to acknowledge members' efforts.
I can't help feeling I've done something wrong.
Regards
Symon.
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As far as I'm concerned Symon, you've not done anything wrong - you've expended a considerable amount of effort on this project, successfully making both the Manhattan style Board and the PCB that I designed, and have given feedback on those, so all credit to you - I'm sorry if you feel that I've not acknowledged your efforts. You're right in saying that as far as we know, you're the only person to have built both versions, and the only other person who's said that he's built one is Barrie - 'Bazz4CQJ', so very well done on that to both you and Barrie. I know that Gary Tempest, who has kept up to date with the thread, will be pleased that it has stimulated interest.
In Post #104, 9 July, I stated:
That's a considerable effort Symon, but built for a tenth of the cost of a Wellbrook, it's worth that effort - leastways, I think so. I'm sure that when Gary spots your post he'll be well impressed. I do hope it passes its 'MOT' - 'Moment Of Truth' and that you're as impressed with its performance as I and several others have been.
Every good wish with it.
End quote.
But you are right in feeling that I've largely lost interest in this thread.
Back in June I said that for me, the thread had run its distance as it had drifted off into discussions which had no relevance to the original topic, often from those who hadn't read the 10-page BVWS Bulletin article by Gary Tempest and had no intention of building it. Topics such as Loop antennas in general, their orientation, possible rotation, performance on short waves, other designs, possible fake transistors and other types than those that Gary used. I don't mind that a bit and certainly wouldn't wish to inhibit debate, but such discussions hold no interest for me. That said, I have written 19 comprehensive posts to answer queries that others have raised.
The project was conceived as a compact loop amplifier which would reduce background noise, increase signal strength, could be unobtrusively sited indoors or outdoors, and built at a fraction of the cost of a commercial alternative. I was able to compare it with the 60ft horizontal wire aerial I was using up till then and the results were far superior, so for me, that was mission accomplished. But homebrew is about experimentation and if others wish to develop things further, that's fine by me.
At the outset, I thought it might attract maybe a dozen responses relevant to the PCB design.
This thread has now had 164 posts and almost 12,800 views so has clearly stimulated interest, even though much of it has little relevance to the original post. (Gary posted the full BVWS article on another forum on 24 October 2016, since when it's had 820 views and just two responses - one the same day saying 'well done', another nine months later on 27 June 2017 from someone who had a Wellbrook that had failed, and wasn't incline to fork out £100 to replace the amp, so made one along similar lines, using a couple of transistors, as does the Welbrook I believe).
In post #43 on 14 June I wrote:
Quote:
I'd just like to clarify that I started this thread not to give full blow by blow details of the ten-page article written by Gary Tempest, which featured in the Autumn 2016 issue of the BVWS Bulletin, but to say to those who had received the Bulletin, wished to build the project and had PCB making facilities, that they might want to consider that option, rather than the 'Manhattan style' board. That said, for a one-off 'Manhattan style' is probably as quick to build if not quicker, and for most constructors, would be the simplest option.
Subsequent posts have sought additional information and have queried the rationale which caused Gary to choose the 2N5109 transistor. Those queries can only be answered by quoting yet more information on the forum from the article, which is of course BVWS copyright, and as a member of the Society and occasional author of Bulletin articles myself, that was never my wish nor intention.
I'm pleased that Gary's design has attracted some interest, but for me, I think this thread has now run its distance and there is little more that I can add. Others may by all means wish to continue discuss and debate technicalities and properties of a wide range of transistors, and the merits and performance of magnetic loop amps, of which there are any number of designs out there.
In due course, it would be nice to hear some feedback from others who have built Gary's design, on their impressions of its performance.
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That remains my view and I've since moved on to other projects, about which I've posted.
(As far as I can tell, only Symon and Bazz have given feedback on their experiences in actually building Gary's design).