FDIM: Bob Crane Interview with Preston Douglas WJ2V

WJ2V with Chuck Adams and Zack Lau

Our ace journalist in Dayton Ohio caught up with QRPARCI President Preston Douglas, WJ2V. 

Congratulations to Preston and QRPARCI for a successful FDIM event. 

Pete and I will heed his warning! 

Listen to the interview here:

http://soldersmoke.com/FDIM17WJ2V.mp3

Thanks Bob! Thanks Preston!

Old Timer Needs Soldering Help

I believe Harold is in Elk Grove California.   Is there anyone out there who could help him?  If so, please send me an e-mail at soldersmoke@yahoo.com


Bill

I'm a very elderly ex-ham living in Elk Grove and my current project is putting together a World War II military surplus IFF. This requires that I solder cable to small circular connectors and I no longer possesss the eye-hand coordination to do this. Do you jnow of any ham who can help me with this-he or she would be reimburses, of course Thanks for you your help

73s Harold S Meltzer ex W2OZX.

The Leon Lambert Crystal Radio

Above you see another gem from the Manassas hamfest.   I didn't know what this was.  And I don't think the seller knew what it was either.  I think I gave him 5 bucks for it (as it turns out that is close to the original 1925 price).  It was only in the course of looking up yesterday's Philmore Fixed Crystal Detector that I happened to spot a picture of this thing.

There is not much to it.  That nice dial is mechanically connected to a sweeper arm that runs along a big coil.   The galena and cats whisker were apparently held in place by the Fahenstock clips on the front.   Leon Lambert made these things in Witchita Kansas around 1924.   He started making them without the fancy wooden box, but one report says he found a good source for the enclosures:

In 2004 Dale Davenport wrote:

Leon Lambert's crystal sets show up maybe as or more often than most other brands from that time period apparently, particularly in the Midwest, There are quite a few variations though: some have a little metal tag tacked on, usually on top front center, some do not have a tag at all. Detectors vary some as well and I've seen them with Erla fixed detectors. One thing is more or less constant it seems, and that is the little wooden boxes they are mounted in. I cannot verify the story other than from observations, but was told quite a number of years ago that the boxes the Lambert sets are mounted in were used to ship sticks of chalk, packed in saw dust, to schools. Lambert supposedly had a deal with someone with the local school system to acquire these as they were emptied. I have owned one example, and have seen other examples of these sets that show some pressure marks on the flat sides, near the corners, where they apparently were packed in bundles, and the strapping tape used to secure the bundles left an impression. This seems to indicate that the story might be true and they might be leftover marks from the box's days as a chalk shipping box.Has anyone else heard the story or can anyone else offer more details on this theory?  From: http://www.antiqueradios.com/forums/viewtopic.php?t=36735

Here's a picture of the unboxed version -- you can see here where the galena went:

From: http://www.gifarmer.com/radio/crystal.shtml

And here we see Leon himself:

From: http://makearadio.com/index.php

More info: http://www.radiomuseum.org/r/lambert_long_distance_2.html

http://www.radiomuseum.org/r/lambert_crystal.html

The Philmore Fixed Crystal Detector

I was at the Manassas, Virginia hamfest on Sunday.  An old timer had a box of crystals for sale.  It was obviously the kind of "box of rocks" that many of us have in the shack.  There was a very wide variety of crystal packages in there, perhaps the widest range of possible styles.  In  among the modern computer crystals and WW II FT243s, I found one from the earliest days of broadcast radio.  The Philmore Fixed Crystal Detector is really just a chunk of galena with a phosphor bronze cat whisker held in place by a spring. Philmore apparently went ahead and found a "sweet spot" for you. 

N2HTT was working with on of these last year: https://n2htt.net/2016/01/17/a-complete-digression/

Of course, I liked the New York City connection.

I will see if this old thing still inhales.

KM4FNQ's FB Michigan Might Mite

Bill:

transistor: 2n2219a metal can with homemade aluminum heat sink
resistors: 27 ohm 2w 5% metal oxide; 10k ohm 1/4w 5% carbon film
polyvaricon capacitor: from an old am radio 9pf to 149pf
capacitor: 0.047uf polyester film (473)
coil: 1.25in. pill bottle with electric motor magnet wire: 0.017in.
       primary: 45t, tap: 15t, secondary: 6t
crystal: hc49/u 3.57 mhz

key: momentary-on switch from radio shack going-out-of-business sale

board: fr4 1oz copper, 3inx4in

pads: me-squares from qrpme.com

dummy load: six 300 ohm 3w metal film resistors

next step: low pass filter.

73 de Ken  KM4FNQ

LTSpice .asc file for the Organic Chip NE602 Rig

A link to the .asc LTSpice file for the NE602 rig  appears below.   Perhaps some brave soul  more skilled in LTSpice than I am might want to turn this drawing into a real simulation.  Some of the parts (like the NE602s) have actual simulated components behind the drawings.  Others (like the relays and the LM741 and LM386) are just drawings.  But go ahead and flesh this thing out.  Who knows, it might come to life in the PC and start making QSOs on 40!

Here is the .asc file:  http://soldersmoke.com/NE602 Rig.asc

My Organic Chip Rig with an LTSpice Schematic

CLICK ON IMAGE TO ENLARGE

This is a rig that came together through a process of Spontaneous Construction.  It started out with an innocent effort to get  an Organic Light Emitting Diode display to work with an Si5351/Arduino combination.   Then I figured I'd make a superhet receiver with it.  Then Pete said I should make it a transceiver.

Most of my earlier transceivers so closely followed the schematics of Farhan or others that it didn't really make sense for me to prepare a new schematic.  This one was different.  So I decided to prepare a proper schematic.  I tried a few of the free-ware CAD or drawing programs, but each of them had a learning curve at the entrance. So I turned to LTSPICE.  I have already climbed that learning curve.  

The results appear above.  Click on the image to make it bigger.   I'm sure there are errors in there.  And I think some of my parts choices might be less than optimal.  But it works well.

The filter was deigned with the help of AADE software.

The idea of using two NE602s with a filter between them came (I think) from the Epiphyte.

The band pass filters were designed with ELSIE software.

The RF power chain is mostly from Farhan's BITX40 module, with the pre-driver and driver modified for a bit more gain.  Farhan's amp is the most stable power amplifier I have ever used.  It hasn't given me any trouble, even at 20 Watts. Strongly recommended.

The microphone amp is derived from the 741 op amp circuit used in the (in)famous Wee-Willy DSB rig.

The receiver AF amp also comes from Farhan's BITX40Module.

Please let me know if you spot errors or have suggestions for circuit improvement.

A link to the .asc LTSpice file appears below.   Perhaps some brave soul  more skilled in LTSpice than I am might want to turn this drawing into an actual simulation.  Some of the parts (like the NE602s) have actual simulated components behind the drawings.  Others (like the relays and the LM741 and LM386) are just drawings.  But go ahead and flesh this thing out.  Who knows, it might come to life in the PC and start making QSOs on 40!

Here is the .asc file:  http://soldersmoke.com/NE602 Rig.asc