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Hi been playing around with ft8 on 160m.. on psk reporter heard in vk etc.. ( when band open.) tx and rx antenna is a Marconi T. However rx in said directions from here is poor. ( see below.) Live

I have a SAL-20 antenna for sale.? Contact me off list for details. 73l Bill, WA2DVUCape May. NJ609 425 8651bill.riches@...

@Dave, Martin i am on a weekend trip. Will be back soon and try to answer your questions. regards, Fred

I couldn't agree more, Fred. Audio, yes. ... RF, likely not. But what about below 100 kHz where most of my application lands? I'm primarily interested in "DC" through 100 or so kHz. Dave -

Hi Fred, I've had a look at your circuit diagrams, and wondered if you could clarify a point for me. I'd assumed that placing an active current source, in place of the source resistor, would set the

A better way to improve large-signal handling is to replace the source resistor of the input FET with an active current source. This increases linearity and also reduces the gain loss of the source

Yes i know, but this is comparing apples with oranges. The Ikin Amp is a balanced very low Z Input amplifier for magnetic loops. The current discussion is about Hi-Z impedance change amplifiers for

There is a reference here to Andy Ikin's paralleling of FETs, lowering the noise figure. https://www.shoc.ch/wellbrook.html The antenna uses 8 very high gain JFETs in parallel push-pull with a

Yes parallel JFETs can lower the noise at the signal gain is linear and the noise being random adds as root 2 or 41.4% for each doubling. Eventually the gate capacitance will be an issue. Andrew

I would agree. However, I seem to remember reading that parallelling FET's can improve the overall noise performance, but can't find the reference to quote. It does however reduce the input

I built this circuit and used it for many years. In fact is was my first antenna for NDB DX 10 years ago. I started with 1 FET and experienced some IMD from local AMBCB stations. Then I added 3 more

I doubt, that paralleling FETs in an reactance driven HiZ? application is worth the effort. The noise figure of an Hi-Z FET Amplifier ist primarily dominated by the thermal noise of the Gate bias

The following photos have been updated in the Azi-Loop Self-Supporting Structure for Transportable / DXpedition Use ( /g/loopantennas/album?id=301249 ) photo album of the

The following items have been added to the Files area of the [email protected] group. * /MODIFIED AMRAD PREAMP - 20 MARCH 2025.docx (

/g/loopantennas/files/Modified%20AMRAD%20eProbe%20Antenna.pdf

That will teach me for DL'ing so quickly LOL.....can you post a URL to the corrected document? 73 Gedas, W8BYA EN70JT Light travels faster than sound..... This is why some people appear bright until

I made the corrections that Martin mentioned and I also add the Bias adjustment procedure to the posting and deleted the 2 original postings. ?Everett N4CY

Thanks Martin, I will correct it. Everett Sent from the all new AOL app for iOS

Thanks Dave! Andrea [email protected]> ha scritto:

Hi Everett, Incidentally, note that in your schematic, one of the input diodes, seems to have the wrong polarity. Personally, I'd bias them to ensure decent IMD performance, but maybe you have