Left Coast Political Scene

The banter on the air these days often drifts (not LC VFO's drifting) to the rig they are running. Most often it is a Yaesu or Icom and at the higher end is the FLEX or Apache Labs.   Notable very few if any homebrew rigs. Have you ever wondered about the SSB rigs being used in 1961? Those who owned a gold mine or were single might have a Collins KWM-2*, but many had Drake, Hallicrafters, National and the ever budget conscious Swan Rigs.  Herb Johnson who started Swan Engineering later Swan Radio was a visionary and started off by producing monoband units for 75, 40 and 20 Meters. The aim was Mobile operation as this was Cycle 19. I saw my first ever Swan SW-120 in February 1963 when I was a senior at Penn State. One of the professors had the SW-120 mounted in a Sunbeam Alpine. Later that same year when I headed out to Midway Island, I had a National NCX-3 -- should have bought the Swan 240! About 15 years ago I bought a SW-120 and two years ago the SW-175 and two weeks ago a ...

Recently I was asked what is the Simplest Receiver? Hands down it is the Direct Conversion Receiver! Today's post is to talk about that receiver topology made all the simpler by the Wizard of Portland and a new small board he will be selling. I have a couple of advanced copies of the board and want to share some info with you about a DCR project using two J310's as a DGM. You can find more info on the J310 DCR here . Consider this as leaking-edge info on Todd's new product thus sign up for his newsletter to get the release date and the pricing info. Go to https://www.mostlydiyrf.com  for the sign up. Some observations about the unit -- it is small and K7TFC has made it easy to use. There are holes at the connection points so you can solder stiff wires in the holes and make these plug-in units for socketing. In the event the range of your security blanket is limited to a Manhattan pad then with the stiff wire that can be soldered to the pads. In the most recent issue of the ...

A recent acquaintance and newfound friend suggested I cover the tube versus transistor dilemma. Some Blog readers may even be saying why are you wasting my time with this subject. With a degree of certainty if you were born after 1960 then likely you have not dabbled a lot with tubes. So, it is somewhat of a question of familiarity with the use of tubes that will position most blog readers. There are definite pros, cons and negatives to the use of tubes.  Your antenna really doesn't know if the fire in the wire is coming from a tube or transistor. When I use my several pieces of Collins gear the station at the other end does not know that it is a tube radio until I tell them. Now if it was a Swan tube radio or perhaps a homebrew SS using an LC Analog VFO likely the other station would know because of drift in the signal.   The real negative with the use of tubes is that high voltage is present and can kill you. In line with the power supply concern is the operation in th...

  Today's post reminds me of a cheesy 1930's black and white movie where this group of adventurer's lands on a remote Pacific Island and finds that the natives daily feed one of their own to this monster creature. The objective is to ward off the eating of all of them. They do not understand that in time the monster devours all of them! I guess I sense the need to feed you, the blog readers, with something new each day otherwise you will shift your interests to The National Enquirer or Fox News.    Innovation! Our hobby is a like a large circus tent that has been divided into sections. One small section contains the group of homebrewers who are constantly looking for some new adventure. Perhaps it is with a project from the good old days or perhaps venturing forward with something involving leading edge technology.   Yes, the rest of the tent is involved with contests and operating. Thank goodness for all those guys shouting CQ POTA as that provides source signals wh...

At times we need to include some form of metering in our homebrew rigs. No, we will not be installing a Nano VNA in a transmitter. But often a current meter is needed like in a tube type amplifier. Real panel meters like the Simpson, Tripplet, GE, and Westinghouse of old are still hanging around but can be expensive especially for some specific ranges that may be needed. Yes, you can buy the Chinese ones for a $10 --but just not the look of the old-style round meters. So with a bit of meter magic I am going to share how you can take a basic 0-1ma meter of old and make it read up to 200ma (or any range) for this specific application.  Enter the Meter Multiplier which is all based on simple mathematics. Basic electronic mathematics states the current entering a node equals the current leaving a node. So for our example I1 which is the source current is the same value as the sum of I2 and I3 which are leaving the node.  Our 1st equation.  Now by Ohms law E=IR, the voltage dr...

Shame on you! We are not talking about the criminal trial of a former president nor the situation in the Middle East. The subject is the Bias setting on your IRF510 amplifier circuit. Pout in dB and Bias level from 3 to 4.3VDC Above is a representative typical IRF510 Linear amplifier circuit which of course is shown in LT Spice. V1 is the normal supply voltage at 12VDC and V2 is the Bias Voltage shown as 3VDC and V3 is the driver signal from prior stages shown at 5v.   This is a really interesting circuit to simulate as you soon see that many of the component values if changed, do little to affect what is coming out of the pipeline. BUT one or two of the components have a significant impact as even a small change will dramatically affect the output.  Now up front the 3VDC Bias is way too low but we need to start with that to see how the BIAS is a major player. At 3VDC, the output is less than the input.   We hardly hit 0 dB at 30 MHz. So that is not a good set point! We h...