Free Semiconductors still available from KE6F

18 August 2016, 19July 2017,  27February 2018


Bob, KE6F, has a huge junk box that he is is willing and pleased to share with other experimenters.  Here are the items that Bob  presently offers:


BF998 Dual Gate MOSFETs.     These are real gems.   He still has them.    They are SMT parts with four terminals.   They are easy to use in a breadboard and provide lots of gain and low noise up through VHF.   A 50 MHz low noise amplifier is shown by clicking here.    To get a "pinch" of these parts, send a regular sized (business) SASE with a "Forever" stamp to Bob and he will send you the parts.  

Incidentally, the BF998 is not an obscure dual gate part from the past.    Rather, it is an active component that is still listed in the Digi-Key and the Mouser catalogs of August, 2016.     If you use these in, for example,  a club project, there is a good chance that they will still be around for a while.   (I just checked and Mouser still has them listed in July, 2017.  w7zoi)

TO-220 Power MOSFETs.    The types are the BUZ101 and the BUZ104 from Siemens/Infineon.   These are new leaded parts.   The specs look like these would work well for RF power amplifiers in the low end of the HF spectrum.    Bob indicated that someone has used them for this.    If you want some of these parts, send a LARGE (8.5 x 11 inch) SASE to Bob with a couple of dollars of postage.    Don't send money.   With the SASE Bob will send you "a fist full" of the parts in foil wrap.
The data sheet for the BUZ104L lists the part as 50 V max drain voltage, 17.5 A max current, 0.1 Ohm max Rds-on, 60 Watt dissipation, and typical gate-source threshold of 1.6 volt.  

Here's what Bob, KE6F, had to say about these FETs in a recent email:

    Let your web followers know that the BUZ104 fets came from a surplus dealer many years back and were end of production parts from a now extinct Silicon Valley company.  BTW I'll include some other BUZ fets in the mix BUZ 101 and BUZ 103 but I will not be selective as I just grab a bunch from the box when I make up the Free Bee shipments.  I'm also sending some TO92 2n3904s that came from a bunch of stuff I bought from a recycle place that got a pile of the remnants from the Grass Valley Group closing.  Once again for the power fets I need and SASE with at least 3 bux in postage attached.  Please no cash and I can't supply specific units; it's just a grab bag.
Our old friend Jeff, WA7MLH, has been experimenting with the BUZ104 parts, mainly building push-pull power amplifiers operating from a 13.5 volt supply.   He has been able to extract 40 watts, or more, on 80 and 40 meters, with 20 dB of power gain.    Each FET is stabilized with a drain-to-gate network consisting of 330 Ohms (3W) in series with a 0.1 uF.    The drains are protected with 38 volt Zener diodes.    Each FET is separately biased.    Gain and output power drop off on 20 meters.    Higher power supply voltages resulted in broken FETs.   Jeff speculates that the failures were from gate-drain breakdown, although more measurements are required.    
And There is Even More:   

In one of Bob's notes, he also mentioned other goodies.    Here's what he had to say:   BTW I also have zillions of 3 mm and 5 mm Red, Yellow and Green LEDs for free along with zillions of SMT capacitors in the 0.1 ufd and 1206 packages along with zillions of little dual npn SMT and single NPN smts and 5 zillion diodes smt.  Please let your readers know that the stuff is available as grab bag assortments free for the asking with the receipt of a large envelope with three dollars postage attached. Please no cash and paste the stamps to the SASE. 
Again, Bob emphasizes:    DO NOT SEND MONEY.

The above SASE conditions apply to experimenters in the USA.    If you are elsewhere, please contact Bob for details.

The address for the parts is
   Bob Miller, KE6F
   9239 Knights Lane
   Wilton, CA 95693

Bob's email is  millerke6f@aol.com

Many thanks Bob for your continued generosity.