Alaskan Road-Kill Microphone

I got a kick out of Paul's message from Alaska -- on my bench I have an almost identical project, including the sink strainer (see below).  And of course the now-iconic SolderSmoke podcast mic is just an electret element inside what used to be an IKEA floor lamp. 

N2CQR Lamp Mic 

Hi Bill and Pete,

I have been following your and Pete’s adventures on Soldersmoke for a while and want to say that each episode always brings some of my past experiences to the surface.  I have been fiddling with radios and electronics for over 60 years, licensed since 1964.

I needed a mic for Bitx40 build and started thinking about this as I was working on other projects. Every day I walk a mile and a half to my mailbox. Wednesday’s and Friday’s happen to be the days of trash pickup and people put the trash bins out next to the road for pickup.  Last week I spotted a little desk lamp sitting on top of one of the trash bins with the cord cutoff so on my return from the mailbox it was still there and it followed me home.  (fig1)

Removing the shade left a flexible vertical support for a mic, (fig 2).

Your recent podcast you mentioned your D-104 microphone, that was my first mic once I had phone privileges back in ’65.  Scrounging through my treasure box I came across a 1 ¼” to 2” PVC pipe coupling that looked just like the basis for a mic. A few hours of mediation and a couple hours at the lathe and mill produced a mic with stand and a PTT switch (fig 3).

Some scrap bin aluminum and a free lamp from the trash and another hour at the lathe, (fig 4 & fig 5). And yes, it has some heft as the base has a large hunk of cast iron in it. Will admit I spent $1.24 for the sink strainer that sacrificed itself to become the grill ala D-104.

The self-satisfaction of building your own gear and accessories is one of the rewards of this hobby, can’t buy that in a store. And repurposing someone’s trash into something useful is a plus.

Keep the soldering iron hot.

73’s

Paul KL7FLR

Wasilla, Alaska

PS JoAnn’s is one of my favorite places for finding useful materials.

Please Help This Guy

From time to time we use the SolderSmoke blog and podcast to try to help those in need.  We have close ties to the Dominican Republic and often become aware of people who are in real trouble in that country.  Here is case of a man who really needs some assistance.  Please take a look and consider helping him out.
https://www.gofundme.com/ramons-medical-treatment

More on K0EOO's Amazing Homebrew SSB Rig

Hello Bill,

The rig was my own design based on an article by Guy Gillet, ON5FE, published in QST, Jan 1970. (Editor's Note:  ON5FE's article also appears in the 1970 edition of the ARRL's book "Single Sideband for the Radio Amateur.") His article had some features I wanted and became the guts of the transceiver I finally came up with…  The rig took me some 2-4 years to complete mainly because I keep changing circuits and improving performance.  For example, I started with a 4 digit counter using nixie tubes and ended up with 7 digit 7 segment LED counter summing the BFO, VFO and HFO.  I also later added the keyer and CW audio filter and so on…..

Other than the outer cabinet from LMB, I did all the metal work complements of the metal shop at our lab at CDC’s advanced design lab.

Pictures show bottom with RF bottom plate installed and bottom view of RF section with plate removed.  Front panel and picture of top cover open showing the plugin PCB’s.  Cannot see the digital counter display board in any of the pictures.

Here are a couple pictures of the old girl.  I’ve added a description of the rigs features:

Features:

• Dual conversion, first IF tunable, second IF fixed
• RF clipping
• 7 digit readout of exact operating frequency (digital summation of BFO, VFO and HFO)
• All solid state except for 6146 and 12BY7 driver.
• RF gain is 0-60dB step attenuator on input
• Dual VFO’s for separate receive/transmit or transceiver A/B
• Modes are USB/LSB/CW
• Auto zeroing S-Meter
• Built in VOX and PTT
• Built in CW keyer and sidetone generator
• Built in CW audio bandwidth filter
• Built in Tune mode
• Built in RF Clipping lever control
• Built in keying to PTT external amplifier
• Output signals for SB-610 scope receive signal monitoring
• Output signal for SB-620 Scanalyzer panadapter
• Diode T/R switching through out the radio, no relays, totally silent TR switching

Well Bill, you opened Pandora’s box when you asked me for more details, hi, hi…  You can almost see the buttons popping off my vest as I reminisced the feature list…

Regards, Dennis, K0EOO

K0EOO: Homebrew SSB in 1974

It is not everyday that you get on 40 meters and run into a guy who has actually built a single sideband transceiver.  But that is what happened to me today.   I spoke to Dennis, K0EOO.  He  showed an unusual interest in my BITX DIGI-TIA.  He went on to explain that he had done some homebewing himself.  In the picture (from 1974), right next to his Vibroplex bug we see his homebrew,  80-10 meter,  dual conversion,  solid state (except for the 6146 final) SSB transceiver with digital readout.  Wow.  That's a beautiful rig.  

Off his right shoulder is a homebrew 700 watt amplifier using dual 4CX250s. And behind his left shoulder we see a homebrew tube-type receiver.

Note the look of pride and determination in OM's eyes.  You can just hear him saying it: "Rig here is homebrew."

More pictures of Dennis and his rigs (including some amazing vintage gear)  here:

https://qrz.com/db/K0EOO

http://www.isquare.com/millen/members/k0eoo.htm

http://www.vintagessb.net/k0eoo.htm

Thermatrons Al Fresco: W4GON's FB HB AM Rig

I was listening to 7290 kHz with my BITX this morning and I heard W4GON say his AM rig is homebrew.  So of course I fired up the DX-100 and the HQ-100 and gave Joel a call.  Conditions were terrible but we had some support from the radio gods.  

From Joel's QRZ.com page: "It uses a pair of 6L6s in Push-Pull Class AB1 high level plate and screen modulating a 6146. I still have a lot of work to do on this rig, like building an enclosure, but it works and I just couldn't help but getting on the air with it!"  

I think it is a thing of beauty. 

Let's Give Jason NT7S Some Support!

Most of us are using Jason's code and his Arduino Si5351 libraries.   We now have an opportunity to help him continue to come up with the innovations that keep things moving forward on our workbenches.  

Consider becoming a patron.   Learn more here:  

https://www.patreon.com/NT7S

Thanks for all you do Jason!  

"So You Want To Build?" Words of Wisdom from Pete Juliano

Everything on Pete's blog is worth reading, but this article was so good that I could not resist posting a link to it here. 

Tribal knowledge from a leader of the homebrew tribe: 

http://n6qw.blogspot.com/2017/08/a-new-line-of-transceivers-difx.html