Tech Forum Questions

Ransomware is malware that encrypts your drive so that you cannot access it without buying a key (password). About half the time, the mark pays the money and doesn’t get the key, or files are so damaged the “key” is useless. Best thing to guarantee safety from ransomware (and other malicious malware): backup (or better image) your drive(s) as often as feasible and store the image disconnected from the PC. You can always revert to that image.

In addition, use anti-malware software suites with good reputation, such as Avira, Avast! or Kaspersky. Or use an operating system less likely to be attacked, such as Linux (though Linux is not invulnerable, it has a far lower incidence of malware).

To clear things a bit, there are two basic types of malware, one being virus-based, which is more typical with many variations. The other is classified as Ransomware which technically speaking is a “virus” of sorts, but is classified as Ransomware because of the way it behaves, namely that your computer becomes ransom to the attackers which demand you pay a ransom to get back your computer.

Ransomware is a relatively new form of infection compared to the virus infection. Most anti-virus/anti-malware programs - and that includes popular brands for both Windows and Macs (yes Macs can get infected), are not generally engineered for Ransomware protection. However, recently that has changed due to the increase in Ransomware attacks. Programs such as Malwarebytes Premium (www.malwarebytes.com/premium/), which has recently been renamed to Malwarebytes 3, claims to protect PCs from the garden variety of virus infections as well as protect you from potential Ransomwar attacks.

In terms of how a Ransom attack works: generally, in terms of becoming infected, it works similarly to any other computer virus; a computer can be infected by a drive-by (visiting a website that has a Ransomware virus), or more directly by clicking on an email link that looks legitimate but is a phising scam that infects your machine with the Ransomware virus. Once your machine is infected with the Ransomware, depending on the nature of the Ransomeware, it will begin to encrypt files on your hard disk. In addition, it will in effect, take over your machines so that you really can’t do anything with it until you pay-up. However, there have been many instances where the bad actors will not provide the key to unencrypt your machine even after paying the Ransom.

In terms of “fool proof” protection, there’s no such thing as fool-proof with virus or ransomware infections, The only almost fool-proof protection would be to never connect your computer to the Internet or ever let someone insert a USB stick into it which could infect your machine.

That doesn’t mean you can’t protect yourself from being infected in the first place. The best protection at this time is (and this is not an exhaustive list):

• Don’t click on any links that look strange.
• Don’t open email attachments from anyone you’re not expecting.
• Don’t visit sites and click links on them that you’re not sure about.
• DO install anti-virus/anti-malware on each computer in your house or network setup - Malwarebytes 3 is a good choice - there are other but they are more complex to work with. There is also a free version of Malwarbytes but it does NOT offer Ransomware protection, so stay clear of it.

The final tool in your arsenal that will above all others be required if you can’t remove a Ransomware infection is a backup. I tell this to my clients:
Do an image backup of your computer’s hard drive; an image backup is a “snapshot” of the entire hard drive, including the operating system such as Windows, In the event of a Ransomware infection (or even a hard disk failure) restoring your machine using the image backup will restore the machine to the time the image backup was made - everything will be there but without the Ransomware.

The obvious concerns with an image backup is that if you back up your machine on weekley basis, your backups will be a week old. Whenever you restore your machine using the last image backup, whatever files were added between the last image backup and the point you restore the machine will not be there. But, you will have the certainty that your machine has been restored to a ramsomware free state.

To do an image backup requires that you have backup software installed. I personally use Macrium Reflect (there are other programs) to create image backups and it has saved my bacon on a number of occasions. It takes a bit of learning to use, but once you understand how to make and restore backups you will have an “ultimate” restoration tool in the event Ransomware somehow gets through, or if your hard drive fails and the machine can’t boot.

Macrium Reflect offers a free edition of their backup software at www.macrium.com/reflectfree. The free edition will allow you to create image backups of your hard drive and restore the hard drive from the image backups. The image backups should be stored on an external USB hard drive (if you store the backups on your PCs hard drive and it gets Ransomed you will be unable to use the backup image). So If you currently don’t have an external USB drive I would suggest you purchase one of at least 1TB size to store the image backup to.

In addition, you will need a USB stick (16GB) to create Restore Media that is used to boot your computer in the event you want to restore your Ransomed computer’s hard drive.

Lastly, using any backup program requires that your computer be able to boot from a USB Stick (or CD ROM drive). Many computers these days are optioned to just boot from the internal hard drive on the computer. So, for restoring a computer from a backup image requires that you can boot the computer using a USB stick (under the presumption that the internal hard drive is defective or Ransomed).

If your computer can’t currently boot from a USB stick you will need to alter the BIOS so that a USB device, rather than the internal hard drive, is the 1st choice when booting. And if you have multiple computers in your household you’ll want to install something like Malwarebytes 3 and Macrium Reflect on each of them. You can get discounts when you purchase either of these programs for multiple computers.

So, installing anti-virus/anti-malwayre, being security concious and not clicking on links, etc, and doing regular image backups is your best way to stay safe from not just Ransomware infections but most other infections as well. Admittedly, there’s a lot to do to protect yourself but unfortunately, as they say in security, the bad guys have to be lucky only once — you have to be lucky and vigilant 100 percent of the time.

The substrate of most of these boards will be made of FR4 or G10. Both of these are glass epoxy laminates. Some less popular substrates include phenolic or even aluminum.

In addition to the substrate there is copper (obviously), plus solder mask and silkscreen. The solder mask and silkscreen are often made of lacquer or epoxy-based inks. As far as I know asbestos is not used in the production of PCB’s.

It’s good that you’re concerned about personal protection, though. The glass fibers that are released when cutting these boards can still be hazardous, and personal protective equipment is always a good idea.

It’s unlikely you’ll find asbestos in circuit-board material. Most are fiberglass and epoxy. Still, you don’t want to breathe fiberglass dust when you cut a board. A dust mask and safety glasses work well to keep dust out of lungs and eyes.

Most often I use a sharp box cutter or an X-acto knife to score the PCB and then snap the sections apart. The knife doesn’t need to cut all the way through a piece of board. A small coping saw with a fine-tooth blade would also work.

Also look at jeweler’s saws that come with fine-tooth blades. You’ll need a vise or a clamp to hold the PCB steady for sawing.

I have worked with electronics for about 50 years, and with circuit board design for about 30 years. I have never even heard of a circuit board made with any asbestos. Most circuit board material is FR-4, which is glass epoxy — that is, fiberglass. It is usually 0.0625” (1/16th) inch thick.

When cutting or sanding circuit boards you should wear breathing protection — some kind of dust mask — as the dust created by cutting the fiberglass board is hazardous.

You can see more info on circuit board materials here, https://en.wikipedia.org/wiki/Printed_circuit_board.

I cannot say for all boards, but the ones I see usually specify FR4 fiberglass, which is asbestos-free. Of course, grinding fiberglass isn’t ideal either; you should always wear breathing protection while grinding ANY PCB since the dust isn’t the best thing in the world to breathe.

A "proper" PC board is made from epoxy resin with a fiberglass filler or from phenolic resin with paper filler. Any of this stuff would be better if you didn't breathe it, but it's not asbestos. One way to minimize the problem is to cut the fiberglass board with tin snips. That makes little to no dust.

I owned one of these. It uses 12V. It was designed as a vehicle media or backup monitor.

Those monitors are designed for automotive use and run off 12V, I have not measured the current requirement but it is not very high. Most of them require a valid video signal on one of the inputs to turn on, without that they go into standby mode.

These look like automotive backup camera displays, if so, they should use 12V for the power supply. They may also need a signal that tells the display that the car is in reverse.

The one I have in my van can be turned on manually with a button on the display so it is not powered by the backup lights.

This monitor looks like one I have used in the past and they need a video signal input before they will power up. The 12 volt 500 ma power supply should be fine.

These monitors are usually used for backup cameras in vehicles, which means they likely use 12 VDC. You didn’t mention if you had tried to feed a video signal into them when you applied power?

Backup cameras are typically wired to the reverse light of the vehicle, so that when you shift into reverse, the camera is powered and sends a signal to the monitor. The monitor then automatically turns on.

So perhaps this might be the issue, that the monitor needs a video signal to turn on?

In the early 60's, the Thunderbird with the sequential turn signals was all the rage. I had a 1960 Chevrolet Impala Convertible, and wanted to put in sequential turn signals. The tail lights had three lenses, the center one was clear for the back up lights, but would accept a red lens too.  So as far as the lights themselves I was all set. I went to the Ford dealer and asked at the parts counter for the turn signal blinker for the Thunderbird. As I was young and naive, I imagine that I thought I would simply connect it the same way it was done in the Thunderbird. Well of course no such luck, and the part was not returnable as it was an electrical part. So here is the short version of what I did, without any schematics, I too am 72 years old and this goes back 60 years or so.

The Thunderbird turn signal device consisted of a small motor to turn four cams. Three of the cams were used to light the lamps in the proper sequence and the fourth cam was used to keep the motor running until it returned to the home position. Somewhat like the windshield wipers on a car. I removed the standard turn signal blinker and placed a short across it, so that when ever the turn signal was on, I had power there for the entire time. The signal to the rear lamps was now either steady brake or steady turn signal. Of course this was not very useful for this application. However, the front turn signal lamps only have either steady power when the turn signal is on and zero power regardless of the brake switch. Exactly what I was looking for. I used the front turn signal to power the motor with one cam connected, to keep it running to the home position after the turn signal power was removed because the switch had returned to the off position. Now my only problem was to get brake power to the lamps when the brakes were applied and turn signal power for the three cams when it wasn't.

The simple solution to this was to simply use a multiple contact relay, one set of contacts for each lamp. The front turn signal power along with the power from the fourth return home cam was used to energize the relay. Of course I needed two relays, one for the left side and a second one for the right side. It worked as expected and I was the envy of the town, because I was the only non ford vehicle with the cool sequential turn signals. The whole mechanism fit inside of a plastic box about the size of a shoe box.

So that was the solution almost 60 years ago.  Today I would still remove the standard turn signal blinker, and place a short across the terminals to give me always on power when ever the turn signal is activated. I would still use the front indicator to tell me when the turn signal is activated, thus separating the brake signal. From there, I would either use some relay logic, or perhaps discrete logic, along with some timer circuits (555 comes to mind) or a microprocessor to generate the the necessary rear sequential signals. My choice would be a microprocessor, today they are very easy to use and program.

If the only input signal that you have is the 12V to the tail lights, you can't get there from here, for the scenarios that you describe, no matter how much "programming" you do or logic circuitry you design. You need to know the state of the brake pedal switch, turn signal switch and the hazard lights switch at their source and not modulated by the vehicle flasher module, which may be wired upstream of the switches.

Consider this scenario using only the 12V tail light signal:

1. At the first 12V tail light signal - All bulbs ON immediately. (any delay could get you rear ended if it is brakes or a quick lane change)
2. If the 12V goes OFF and then back ON within a time calibrated to the vehicle flasher module rate, then sequence bulbs #2 and #3 ON after delays. Use the 12V signal directly so they go OFF when it goes OFF.
3. If the 12V stays OFF for greater than 2x or less than 0.5x the flasher rate, reset the circuit and go back to step 1 .

This scenario should work in all cases except where you are pumping the brakes old school on ice at a rate that matches the flasher. Hopefully , a rare situation. This should be a fairly straight forward logic circuit with RC time constants and comparators or 555 timer ICs. Use pass-through for bulb #1 and relays for bulbs #2 and #3 on the normally closed (NC) contacts, so that a failure of your circuit still gets the 12V signal to the bulbs. (Fun Fact: Basic automotive flasher modules use current draw to determine blink rate. Which is why it blinks faster when you pull a trailer due to the extra bulbs. There are "heavy duty" modules that set the rate independent of current draw and are a direct replacement for most applications.) You will need the "heavy duty" one for your vehicle to get a stable rate to calibrate your circuit.

I used to own a 1972 Mercury Cougar with sequencing tail lights. Maybe you could get the control module from a junk yard. (All models 1973 and older - I don't know about newer).

I am not completely sure how you want the lights to act when the brake petal is pressed, and frankly I would use a PIC style device to implement this, either a basic PIC chip or one of the ones with a higher level programming language pre-loaded (Ardunio, etc).

But you want a way that does not use code. One way to do this would be to use the old standby 555 timer chip. They can be configured as a one shot, time delay device. You can chain several of them in a ring so that each will trigger the next one in the loop. So they will form a ring counter type circuit.

Then, the first 555 will have a steering diode connected to it’s output and then to the base or gate of a power transistor which drives the first bulb.

The second one has two steering diodes and they are connected to the base or gate of the first AND second power transistor.

The third 555 will have diodes that drive three such power transistors. Each of the power transistors is connected to one of the lamps. So when the first timer is triggered, the first bulb comes on. When the second timer is triggered, the first and second bulbs come on, and when the third timer is triggered, all three bulbs will light.

If you only want one light on for each step in the cycle, just eliminate some of the steering diodes. Additional steering diodes can be connected to the power transistors to activate them when the brake petal is pressed. Additional buffer amplifiers may be needed to get the polarity and current correct for this, depending on the vehicle’s system. The steering diodes will isolate the two functions, brake and directional signals. This does not allow turn signals to flash while the brake pedal is pressed.

An additional, exclusive OR circuit (CMOS logic chip) could be added between the steering diodes on each power transistor and the base or gate of the transistor. This would allow all three bulbs to light when the brake petal is pressed and then they would turn off one at a time if the turn signal is activated.

If this is done, then it would be best to use my suggested method for having only one bulb lit at a time by the turn signal circuit. Thus at least two bulbs would be lit when the brake petal is pressed.
You need to consider how to kill the lights when the turn signal is turned off. This could probably be done by adding three additional transistors to ground the timing capacitors of each 555 when the turn signal is turned off.

I can’t visualise exactly why you would want to do this since, on a car, they are discrete circuits. Perhaps it’s for a model? No matter.

You seem to have cracked how to flash and how to sequence the lamps. The problem seems to revolve around cross connection interference.

Have you tried isolating the circuit’s outputs by feeding the bulb through isolation diodes? With a 12V circuit, these won’t be noticeable, and allow the bulb(s) to be earthed as is normal practice. (Remember to select the diode to handle the inlet surge current through the cold bulb(s).)

You might not want to hear this, but the easiest, most expedient way to do this is with one of the cheap Arduino boards available from eBay. There are a myriad of power supplies, (12 VDC to 5 VDC DC-DC converters), and I/O boards, (relay or solid state), which will just plug together with, as they call them, Dupont cables. All of these are cheap, as in a few dollars. The Arduino IDE is free and with the most of the boards, a simple USB cable is all that is required to interface.

Now, while this may seem very complicated, there are tons of online tutorials. The end result is you get to learn something about electronics, programming, and maybe a new hobby.

The other plus is that you can end up solving your problem AND you also have the ability to make your lights do anything you want.

I found a $20 flasher module via a Web search for “turn signal light sequencer.” The device will flash as many as four lights. You’ll need one module for the left-side lights and another for the right-side lamps.

Creating your own controller with simple logic circuits would get complicated because only one signal turns a brake or turn light on or off. Thus, your circuit must distinguish between a constantly-on signal for braking and pulses for turning. You could use a small PIC microcontroller, but you don’t want to learn how to program, which I understand.

If you change your mind and want to start simply, look at the Parallax Propeller FLiP Module (or the Propeller QuickStart board) and use the free BlocklyProp programming tool. It doesn’t get any easier — you simply choose graphical “blocks” and stack them one on the other. Concentrate on the problem and let BlocklyProp create the code to program the chip.

I will use it. How much do you want for it?

I'll take it as I still use leaded solder.

Leaded solder is still available and widely used, both in aerospace and in the repair and rework of older equipment that was made with leaded solder. Many hobbyists including myself prefer leaded solder because it flows better and makes much nicer joints. As long as you don’t chew on it and are not disposing of millions of tons of equipment made with it there is not really a hazard in having or using it. If you don’t want it I would encourage you to give it to somebody else or alternately you could sell it on ebay.

Leaded solder is considered hazardous waste. If you want to get rid of it reasonably, you can take it to your local house hold hazardous waste. Contact your municipality and they should be able to help you out with that. HHW usually is only one or two days a year at your local collection site.

Most countries would consider it hazardous — as you surmise — and it should be disposed of responsibly, according to local regs. (Whoever accepts dead car batteries should take it for free?)

But should you get rid of it all? The fact that you have it at all indicates you’re interested in electronics, either from repair or construction. The important point I’m trying to make is that the two types of solder don’t play well together, so for reliability, older equipment should only be soldered with leaded solder (and vice versa.)

Do some Googling to check it out. Don’t use plumbing lead-free solder for electronics, either! If you’re giving up the hobby, then shame, but so be it.

If you are a hobbyist, why not just use it. Unless you are selling a product in high volume you’re not going to distroy the world. And it’s so much better than the lead free stuff.

Send it to me. Or to your local makerspace or electronics club (or robotics club, model train club, so on). Most of us prefer to work with leaded solder rather than lead-free for a whole host of reasons.

Officially you’re supposed to dispose of it at a local waste materials convenience center, but I just cant see it going to waste when so many of us are looking for leaded solder.

Take it to a metals recycling center that deals in lead (usually those that take old lead acid batteries). It is generally considered hazardous waste, so don’t throw it away in your trash bin.

You might look into see if you have any kind of municipal or county hazardous waste collection facilities as a part of your home garbage pickup service as well. They may have a drop-off location that can take it.

Finally, you might consider donating it to a local maker or hacker space; a lot of people love leaded solder over non-leaded, due to certain properties it has versus the other.

Instead of throwing it away which is probably illegal, especially if you live in CA, why don’t you give it to other hobbyists. Would you take the cost of shipping to send a spool?

I don’t do any commercial work, so using leaded solder is no problem. The cost of solder for a lot of us retired hobbyist is a lot. Also, what diameter is the solder and does it have a rosin core?

You might try old auto-focus cameras and similar equipment. Old micro-cassette players too. These all generally have a bunch of small shafts and pulleys; you could take one of the small pulleys and add a miniature o-ring as a tire.

Another possibility, maybe even better, would be those small micro remote control cars, which were popular a few years back. Or maybe small slot-cars or n-gauge trains?

Another possibility for a tire might be a slice of pencil eraser. Super-glue it to a small piece of piano wire or similar for the shaft.

It's a crapshoot. I worked on 3 Chinese sets in a row that were junk, then came to one that was excellent. Other techs report similar experiences.

Bear in mind that the Arduinos in those kits are clones at best, and counterfeit’s at worst. What’s the difference? Well, a clone is one that could be identical in every way to a real Arduino, but is branded differently “SunDuino,” with that brand’s own logos, styling, etc. A counterfeit, on the other hand, seeks to make its product look as close to the official Arduino (i.e. color, branding, logos, screen printing, color of parts on board, etc) as possible — to confuse the buyer and make their product seem more legit.

That said, whichever you choose is between you and your conscience. Honestly, the quality is going to be nearly identical between that of a clone or otherwise; usually — not always. Pay attention to reviews and such is my best advice. SainSmart, DFRobot, and SeeedStudio are all good sellers of clones.

Something else to keep in mind about these Arduinos: they typically use the CH340 USB chipset for the virtual serial link. This is a well supported chipset, but its something to consider.

An official Arduino uses a secondary ATMega16U2 microcontroller for USB communications. Prior to that, they used the FTDI chipset for USB serial comms. Chinese clones continued to use the FTDI chipset even after the Arduino switched to the 16U2, likely because it was cheaper. FTDI then released a driver update (or something like that) that bricked unlicensed versions of the chip, and caused a lot of grief. That basically is what caused the Chinese clones to switch to the CH340 chipset (plus, it was much cheaper).

As far as everything else in the kits, quality varies, but for the most part, its fairly consistent — again, check reviews.

The biggest problem with these kits will typically be a lack of any kind of instructions, project ideas, or any kind of datasheets on the components. Most of the time, these kits are meant for those who are very self-sufficient in hardware and software. If you’re lucky, you’ll get a CD or a URL of PDFs and software, but I would caution against doing anything with it, particularly if you are using a Windows box, as such CDs and software have been known to be vectors for malware.

Finally, as you have probably noticed, there are sellers out there offering some seemingly “weird” kits or microcontrollers, which you may wonder what the use of them is for.

Most of the time, these controllers are meant to serve as platforms either for hacking, cloning, or counterfeiting well known tools based upon the same controllers (either current or older versions). For instance, there are plenty of clones and “bare” development boards which can be configured to act as a Saleae logic analyzer. Others are meant for other similar products, and some are meant just for experimentation (there’s an interesting set of microcontrollers out there based around a hopped-up 80C51 clone). Oh, and some are meant for experimentation creating flight controllers for quad-copters, too.

Lastly, you may have noticed some of the “rival” ARM-based SOC boards rivaling the Raspberry Pi (such ase the Orange Pi and the Banana Pi, among others). These can be extremely cheap and very powerful alternatives to the Raspberry Pi or Beagle, but keep in mind that they tend to be very community supported in that while they are alternatives, they are typically more popular with hardware hackers in China, so the english-speaking community is likely smaller, and support isn’t as good; plus drivers and such for the boards can be hit-or-miss.

Basically, what I’m saying here is that if you want something closer to plug-n-play, stick with the official Raspberry Pi. But if you want to go out on a limb, these alternatives can offer an interesting reprieve — if you’re willing to dedicate more time.

I’ve only built one kit from China: an AM/FM receiver kit for a small pocket radio. The directions left much to be desired, I had to guess at how to put some parts in. I’m still not sure I put the tuner section in correctly, since the FM section starts well below 88 MHz and ends at around 88.5 MHz. I still need to look over the schematic again to see if it was a misinterpretation of one of the parts installations or not.

I don’t like the quality of the case either but it does sort of work and did so the first time I turned it on.

Now, I have dealt with a number of Chinese companies and had some very interesting experiences. I’ve had returned parts returned back to me along with a full refund. After three months of daily email, I simply gave up and kept the parts as well as my refund, since I couldn’t get them to understand that I’d received a refund and didn’t need the parts.

The bottom line is, as long as you pay using PayPal you are safe and can get your money back as long as you keep good email records and supply PayPal with a full explanation of the problem, such as the item does not work as advertised or it doesn’t meet the seller’s own published specifications. I capture an image of the site’s own specifications on the item just to be safe.

You asked an either/or question. The answer is YES. There are problems with many of these kits. See question 1171 for an example. They also usually have terrible or non-existent documentation. But they do have the material in them to support a great many projects and demonstrations for an incredibly low price. So if you are on a tight budget they are well worth the problems.

A lot of the products from China are cheap clones, some are of good quality and some are not. I buy different type of modules for the Arduino Uno to try, I am working on a TEA5676 FM receiver.

I also support a lot of American electronic parts stores in the USA. I like ADAfruit, as they have a lot of tutorials on the products they sell. This helps greatly with the learning curve on the newer electronics.

The main reason to use an analog (i.e., moving coil) meter is that it's much easier to watch a moving needle than changing digits (even if the DMM has a moving bar in the display). This is especially true when trying to peak an amplifier or similar AC circuit. It's also better to watch a moving needle when testing a potentiometer with suspected dropouts as the needle will visually react faster than even the fastest updating digital display on a decent DMM. Finally, for voltage/current measurements, analog meters need no batteries to operate (resistance measurements is a different story) and they're great for Go/Nogo testing of the presence/absence of a voltage (within the limits of the meter's ranges).

I suggest getting an inexpensive analog meter (ike this one from Sears: www.sears.com/craftsman-analog-multimeter/p-03482362000P?plpSellerId=Sears&prdNo=16&blockNo=16&blockType=G16#) and experimenting with it. Be aware the sensitivity of these meters is usually 2 Kohm/volt (rather than 20 Kohm/volt for a good Simpson VOM), but it's good enough for you to do your own visual comparisons. Plus, you won't be out too much money for one of these units AND, as long as you don't install the battery for doing resistance measurements, you can keep it in the glove box of your car for doing voltage checks if needed.

In the end though, it's up to you to make the final decision on analog vs. digital meter displays for your use.

Audio work can require the measurement of voltages down to the millivolt range. It can also require measurement of varying signals such as voice and music. To best measure these use an “AC VTVM.”

This is an electronic device with a large analog meter driven by an electron tube. They usually have a high input impedance and wide frequency range — often into the 100 kilohertz range. Their input voltage range is usually from 1 millivolt full scale to 300 volts full scale. The meter has scales in both volts and dB — with dB making it easy to measure amplifier gain.

Want to know what the output voltage of a microphone will be for a particular sound? Put the microphone at the desired location in relation to the sound and hook the microphone directly to an AC VTVM. Then just watch the meter scale. (A digital meter will just wildly blink random numbers.)

As an audio engineer, I find that an AC millivolt meter, calibrated in decibels, is essential for audio engineering and repair. For example, to validate the dB attenuation of a Linkwitz-Riley crossover network, or to gauge flatness of a preamp. My 80’s vintage Leader LMV-187 is what I use for this work.

That said, it is easy to build much cheaper and available alternatives. Dual channel VU meter driver boards, and decent VU meters calibrated in dB, are available on eBay. Frontend one of these boards with the ‘Low cost PC Two Channel Oscilloscope’ circuit of the August 2016 N&V, and one has a decent AC metering system for audio engineering. Be sure to AC couple the input to the circuit, for example with 2.2uF non-polarized electrolytic capacitors.

I use my DMM’s for checking power supply voltages, etc. But for audio signal level work, an analog metering system, calibrated in dB, is indispensable.

New analog VOMs are certainly available, but quality is likely nowhere near what used to be standard. What the cheap DMMs won’t show you are fast transient signals; they will either average out the spurious signal (you won’t see it), or they will just completely miss it, due to a slower “sampling” rate.

A high-quality Fluke DMM can be a good choice, but there isn’t any reason not to have an analog meter on your bench, if you can find a good one (tested, calibrated, and known to work well), along with a Fluke.

Sometimes, the slight tremble (noise or hum over the signal) of an analog movement can be seen better by a human than a DMM can update. But for most things, you could use the Fluke (heck, for most things, you could just use an el-cheapo free-with-coupon Harbor Freight throw-away).

Another option to consider, depending on the signals being looked at of course, would be a digital o-scope; being able to sample a signal over a period of time, then going back and reviewing it can be very helpful in tracking down certain problems that can’t be seen otherwise, using other tools.

The use of analog versus digital to me is a personal choice. I work in the 2-way radio field and personally prefer analog meters for several reasons; the first is that it is easier to detect a peak or a null with a needle on a meter than it is trying to read changing numbers on a digital display. In fact, I have never seen a grid dip oscillator with a digital display.

The second reason is that while working on a circuit board and looking for voltages, I can glance up at an analog meter and watch the needle move, and with the proper range set, I have a good idea what the voltage is with just a glance. With some analog meters such as the B&K 290 electronic VTVM that I use on the bench, there is a scale on the bottom with zero centered mid-span which allows me to see if a voltage/current varies from what I have set as the standard I am using, which allows me to set voltage/current to that standard.

While I am an ‘analog guy’ there are times when I use a digital meter. When setting VCO voltages you need a digital meter to accurately set the voltages. Another use where digital is better (in my opinion) is reading the values of resistors and capacitors. A DMM has the advantage of reading capacitors, which analog can’t do. Although, it can be a pain to read resistors on an analog meter due to the logarithmic scale and crowding at the high end of the scale, it does excel at testing pots to see if the operation is smooth by watching the needle.

On my bench I have the B&K 290 analog electronic VTVM, a NLS TT-21 digital meter and for field work a Triplett model 60 VOM. What works for me or someone else may not necessarily work for you. As I said, it’s based on what you prefer and what your requirements are. I would suggest seeing if you can borrow a digital and analog meter, use them and see what works best for you.

I will offer this suggestion if you do go the analog route, go for a meter that has 20K ohms/volt or better, the higher the ohms/volt the better as it will not load down a circuit under test as a lower range would.

There are many differences between DMMs and VOMs. The two which might justify the old timers advice are that VOMs have lower input impedance than the typical DMM and the dial display of a VOM display is easier to interpret for noisy or changing amplitude signals than a digital display. The higher input impedance of a DMM may make readings from old documentation based on using a VOM slightly inaccurate.

Neither of these characteristics really justifies spending lots more money. Many DMMs include a bar graph display which emulates a dial, mooting this difference.

Finally, analog meters from lesser makers are still available in economy markets and auction sites. If you do find those two differences compelling you can satisfy that need at costs comparable to most DMMs.

The question is not Average vs RMS. When dealing with tuning; the question is measuring of Peaks and Deeps. You can’t measure Peaks and Deeps with digital Voltmeter, to do it you need an analog device.

About 50 years ago, Fluke came out with a nice digital multi-meter that couldn’t be used for tuning. After some time Fluke added an Analog Bar-graph that helps a lot for tuning purposes.

Try to look for Fluke Series 170 and you will find what you need. Buy the way, tuning is mainly done in RF equipment and not in audio.

On web page https://www.fcc.gov/media/radio/am-query enter the FCC Facility ID Number which is usually 4 or 5 digits. Note this is NOT the >>> FAA <<< tower number which is often shown on signs posted at tower sites.

For example, I entered 9642 and it properly brought up: WCCO AM 830 kHz ND1 Unlimited A A LIC MINNEAPOLIS MN US BL-- 50.0 kW 9642 CBS RADIO MEDIA CORPORATION with a link location of: https://transition.fcc.gov/fcc-bin/amq?list=0&facid=9642 This link showed a web page with: “WCCO MN MINNEAPOLIS” and with all kinds of details and links.

So let’s say you are motoring about the countryside one fine day and you spot an interesting tower structure. Look around the entrance area and you should see a sign with the FCC Tower Identification Number on it. Let’s use number 1027514 as an example. Go onto www.fcc.gov/ and:

1. Click the Licensing and Databases tab. You’ll be presented with a list of about 25 databases listed by their acronyms. Some of them are intuitive. Others, not so much.
2. In this case, Click on ASR (for Antenna Structure Registration). Partway down the page you’ll find Search with a choice of either Registrations or Applications.
3. Click on Registrations and a new window opens. In the upper left corner is a field you enter the registration number. While you’re here, you can check out the other possible searches such as lat/lon, by state, etc.
4. Enter the registration number and hit Submit. Note that this takes a whole lot longer to describe than to actually do it. A new window opens with the results, typically one line, but a fact-filled line. We now know the FCC File Number, the owner (in this case, WLAJ-TV), lat/lon, city and tower height in meters (307 meters or a little over 1000 feet). By the way, you can also get here by going to www.fccinfo.com/ where the good folks at Cavell, Mertz and Associates have an easy-to-use database front end and a nifty Google Earth plug-in that will give you the callsign for a station associated with a broadcast tower. Note - broadcast, not cell, two-way or other utility tower.
5. On the ASR Results page, click on the Registration Number. A new window opens, chock full of good information.

Another way to go about this is on the FCC home page, click on ‘browse by Bureaus & Offices’ then on the Media sub-tab. The Media home page will appear. Now, along the left side you will be presented with a list of choices. You want CDBS Search. You’ll then be presented with another list of choices which should be fairly self-explanatory. As an example, choose the first selection which is Search for Station Information (as of the date I’m doing this). The new window is a whole bunch of search fields but to keep it simple the first line is Call Sign. In that field, enter the call letters. Pick your station of interest and type it in there. Example - WLW and hit the Submit Station Search button. A new window opens with the results, which are fairly skimpy at this point. But on the far right of the results is a link labeled Click for Details. Another results window opens with more links to more information. But now we can get into the good stuff.

On the Bureaus & Offices / Media home page, select Electronic Filing and Databases along the left side. The new page that opens offers another list of choices, one of which is AM Query, among others. Hit that one and a new query search opens. On the first line enter WLW. Further down, just above the Results buttons you choose how much information you want. Choose the AM Query (detailed output + CDBS Links) menu item and hit either the Results To This Page/Tab or the Results To Next Page/Tab buttons, depending on your preference. You’ll get everything you ever wanted and more. If you’ve got the time, you can easily spend hours looking up all kinds of arcane things.