SolderSmoke Podcasts /////////////////////////////////////////// SolderSmoke152` Posted: 18 May 2013 07:30 AM PDT SolderSmoke issue 152 This posting includes a media file:

Please do check this out. http://nandustips.blogspot.in/2013/05/foxhole-radio-detector-variant.html Many thanks. 73, Nandu.

I'm interested in putting together a 1.25m repeater sometime in the next year and I'm casting about for possible solutions. It seems that I have two routes: 1) modify a GE Mastr II or 2) find a SEA ESP-1000. Using modified GE Mastr IIs is a well-regarded way of doing it, but I am unfamiliar...

HI, I've several VHF transistor that could run about 50W. I wonder if they are able to work under 3,5, 7 or 14 MHz ? Thanks a lot for your answers Teo

I'm trying to build a 80/40 meter receiver and I'd like to be able to switch the RF input between the two bandpass filters. This sort of thing is usually done with relays but I'd like to avoid that if possible. A SN74CBT3306 would be ideal but I think the on-resistance would be too high, thought...

I want to add sockets TO-3 for the pass transistors in my 12 volt power supply. The trouble is I can not find current(I) specifications for the sockets. I really dont know what I should expect for a spec, guessing 10 amps for a good quality unit. Any help would be greatly appreciated. KD4RQE Jimmie

Please do check this out. http://nandustips.blogspot.in/2013/04/a-steampunk-rf-milliammeter.html 73, Nandu.

Here's the link. http://nandustips.blogspot.in/2013/03/a-homebrew-rf-milliammeter.html 73, Nandu.

I just got a Quad Sideband signal yesterday. Here's how it works for AM. When you modulate 100%, you get one on each side, 200% two on each side. They act like additional amplitude, like an amplifier. The more sidebands there are, the louder it will be x1,x2,x3,x4 louder.

Clamshell-looking enclosure on small AC power transformers. Magnetic shielding to prevent interference with nearby wires?

I have a turret drum that came from an old boatanchor (Murphy B40D). Here is the front-end schematic: http://www.portabletubes.co.uk/boats/schem1.jpg I want to use this drum, but I want to employ transistors not valves. Now today, I presume we can select a transistor to replace a valve, and it...

I am working on a simulation for a loop antenna in LTspice and I can't figure out why the signal strength features are what they are. The model uses a pair of loosely coupled inductors to model the transmitter and antenna loop with a separate pair of tightly coupled inductors to model the...

Anyone familiar with the Metheny Corp Madison, IN Model LJM-RB DTMF decoder board? I have two of these on a used VHF Engineering RPT-144 repeater I picked up. I would like to find the schematic for this board. Thanks much, -Jim

I want to make a minus 400vdc supply for my grounded screen QRO PA. I have iron on resist for masking, for solder masking silk screening and PCB etching I'd like to make it look professional. The Solder Masking Iron on is blue and can be used to etch and silk screen I have 5 sheets of 8.5X11. I...

Has anyone else tried these circuits? I have built 2 examples, a 9 MHZ AGC controlled amplifier and a 20 dB wideband amp for a noise cancelling system. BIG problems! The diode string in the source of the FET always biases the J310 OFF. Result, no gain or a loss!!! It took me an hour or two to twig...

In order to connect a 2m/70cm radio and a 1.25m radio to a triband antenna (2m/1.25m/70cm), one requires a triplexer and diplexer. I'd like to cut down on the number and size of equipment to do this. I asked Comet about making a single compact unit that takes 2m/70cm on one port and 1.25m on...

Do digital receivers get discussed here much? I am working on a receiver for the WWVB signal at 60 kHz and am looking at a very low power all digital design in an FPGA. Of course some aspects are still analog such as the antenna. I have been reading about loop antennas for low frequency...

We need less than a gallon of transformer oil for coolant. Does anyone sell such small quantities? -- A host is a host from coast to & no one will talk to a host that's close.........(301) 56-LINUX Unless the host (that isn't...

Has anyone here successfully replaced the antenna jack on a Yaesu FT-7900 with an N-connector? How about for an Alinco DR-235TMKIII? -- David Griffith --- Put my last name where it belongs

I found the schematic of icom's HM-7 hand powered mic. One of the resistors inside is 18KOhm or 1.8KOhm ??? Thanks SV2BFI