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Yes, because it is not the genuine 2SC3357 from NEC/Unisonic, which is obsolete since a couple of years. It is a new part from EVVOSEMI, a fabless Hong-Kong based company, specialised in second

Just an update. DigiKey has 2SC3357 back in stock. They only have 1009, so it looks like they just got one reel in. They are listed as a "new" part, so I think the issue has been supply chain related

yes any off your question Den 2025-03-01 kl. 14:17, skrev Fred M via groups.io:

Lars, what do you mean with "3 m Loop"? Circumference of 3m or diameter of 3m? regards, Fred

I am curioues if any one tested THE lZ1aq Active Antenna Amplifier (model AAA-1C)? with 3m wire loop or even longer wire? 73 Lars sm4ive

Hi All, Very interesting thread. I looked at the circuit introduced. I felt nostalgia for the 2SC1815 and 2SA1015. They like staple foods for us from the 1980s until around 2010. The 2SA1015 was

A helpful free book on PIN Diodes: The PIN Diode Handbook (pdf) ( https://www.ieee.li/pdf/essay/pin_diode_handbook.pdf ) Regards, Fred

Thanks for pointing to the minority carrier lifetime (Tau) measurement. The paper reported the 1N4007's Tau = ~7 uS, phew! This value is way higher than what I have encountered in real PIN diodes (see

OK. Curiosity got the better of me, so I decided to try Dave's (W0LEV) suggestion and make a measurement with my VNA. I happen to have an LZ1AQ loop right under my 80-10 EFHW inverted L. It happens to

If you’re protecting the loop amplifier from own transmission, then you will need to use a relay to cut the power and and ground the antenna input at the loop and the feed. Also placing the antenna

Guessing and throwing ill conceived "fixes" at an ill defined and misunderstood problem is certainly the average amateur method of "solving" misunderstood glitches and possible damaging

PIN diodes have an additional P layer which is why Sarkes Tarzian never got into that part of the technology. ST made some SCR's and 45KV 2 ma diodes were many layers of diodes stacked and soldered

Cool stuff! I have a QDX 80m to 20m band model. Hans couldn't get the 1n4007s to work on 160m or below so there are single band models for MF , LF and 6m. Getting special performance from simple

Sure, there are several measurements available in the

Hi Jim, Thanks for referencing my paper. :-) However, I will not recommend that limiter configuration for protecting the Rx loop. The described Schottky assisted PIN limiter has a ~10 dB lower turn-on

Interesting question. There are interesting amateur tests of the 1N4007/1N5408 as replacements for the Unitrode P-I-N characterised diodes. At least one experiment shows that 1N5408's were lower

Hi Fred, I agree with the points you are raising, with some caveats. In a 50 ohm system, a pair of 1N4148's or similar small signal silicon diodes will limit at somewhere around +10dBm, and second

Icom uses a pair of 1SS302's to help protect the FE of the IC-R75 receiver. They are very fast & I use them in a protection circuit I built for my receivers downstairs in the torture chamber (repair

It is a common misconception that there is a sharp forward voltage threshold for diodes and that there is no current flow below this "forward voltage". A diode is an amplitude-dependent, non-linear

It depends. With an E-field active antenna a single 1N4148 can generate significant IM products. In this case it is better to use stacked silicon diodes or reverse biased silicon diodes. Another