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I have built several from the esign in: /g/loopantennas/files/MikeM_Wellbrook_Clone So far two of he 1530 configuration and one of the 100 configuration have been built and tested.

I can't see anything called "Wellbrook_Loops.Kicad_sch" in the files section, can you provide a link ? Regards, Martin

Yes, I understand that, but if it is close to oscillation, due to incorrect transformer phase, the gain can appear to be much higher at mid-frequencies. I have seen this myself with some

Martin, ?His ALA1530LN clone is working on 7 MHz without any problem, but in not working on 2MHz and below.?Everett

Have you got the transformer feedback windings in the correct phase / direction ? It's a 50:50 chance of being the right way around if you build it yourself, don't ask me how I know :-) Have you

I think you may have a oscillation problem that is causing your problem on the lower frequencies. You need to make the board more compact and you need double sided copper shielding on the board. ?I

Good morning, I'm wondering if anyone like me has made a full working Wellbrook 1530 LN amplifier based on the schematic found in the files section named "Wellbrook_Loops.Kicad_sch." with smd 2SK932

Thank you all for your advice and experiments. It looks good, so I was wondering why I hadn't seen it. As for the noise, I am not too worried. in last year I tried a noise generator with zener diode.

I do not see a compelling reason to use 2N5109 for new designs, it is an obsolete part. Central and Microchip terminated the production. The last direct equivalent, the NTE278 is discontinued since

In all these common base preamp circuits it doesn't matter what type of base bias is used--I've seen a LED used in place of a standard 2 cent resistor, so using a 25 cent zener diode is just another

When regulating Vcc with a zener we automatically insert a simple cap-input Pi network in the Vcc line. I'd check with a scope to determine the before and after noise reduction and to establish the

Zeners are also good noise generators. It could work well, but must be well filtered. Dave - W?LEV [email protected]> wrote: -- *Dave - W?LEV*

Hi All, I saw an interesting article. an amplifier using a 2N5109 at the bottom of this page. https://www.microchem.fr/ayet/atlas/hf_amplifier.html It has a 3.3V zener diode and a 3.3k resistor to

Agreed, and you need 3dB more noise with an actual antenna connected at any specific frequency, in order to ensure that your antenna is constrained by your local noise floor, so a 6dB rise in noise

Just a quick gauge on thermal noise vs. antenna noise: Define (ONLY for the purpose of simplicity) "antenna noise" as the increase in receiver noise experienced by connecting your combination antenna

There is an updated version of John Bryants transformer paper: 2nd look at fabrication transformers for receiving antennas ( https://peditio.net/utility/pdf/bryant2.pdf ) regards, Fred

"Fabricating Impedance Transformers for Receiving Antennas"? is available at IRCA Reprints, #A-155, index at?

https://www.pa0fri.com/Ant/antennes.htm#E ?? Maybe try a different browser. Henry

If anyone is interested, I have several retrofit amps for the Wellbrook ALA1530 loop. They are in a PVC case, and potted. They are a match and fit perfectly on the ALA1530.? ?Everett N4CY

There is a filament known as ASA that is really durable and offers much more UV resistance but it requires a printer that can handle hotter melting temps and has a heated bed.? I have some but have