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Wire-Lists#7: Cold Weather Care for Transmitters, Mics and Receivers

Social Media WireLists7It’s Winter time again! And unless you live in a tropical climate, Winter means one thing: COLD. Regardless of the time of year, many of you also run sound in perpetually cold locales, such as the Arctic Circle, Siberia or Mongolia. Contrary to popular belief, electronics, unlike Husky dogs, don’t actually like the cold. Your transmitters and recorders can deliver reduced performance and even fail to work below certain temperatures unless you take precautions. Here are four areas to pay attention to when operating or storing your equipment over the next several months:

LCD Displays

LCD displays – such as the ones on our transmitters and receivers - use liquid crystal fluid (more like a gel) in the display. Like all other non-solids, the liquid crystal can freeze in cold conditions. Ideally, you should store any equipment with an LCD display in consistent temperatures between 40° and 100°F to keep the liquid crystal from freezing.

What happens if you’re working in extreme cold – such as an outdoor location shoot with wind, snow and ice? Even if you had stored it in a warmer area, the equipment will invariably get colder as you work. When the surrounding air reaches the freezing mark of 32°F and below - equipment will still work, but you may notice the display responding much slower than usual.


A side effect of cold is reduced battery power. Why? Because batteries create power through the flow of electrons from one terminal to another. In cold temperatures, the internal resistance increases and this flow slows considerably, making the battery output more power than normal to power your unit. For example, at -4°F , most batteries will be at 50% of their normal performance level. This results in batteries that don’t last nearly as long as you expect. One way that you can somewhat circumvent this is to replace the batteries at the end of each cold workday, which makes sure that you are starting off each day with fresh power. This is a best practice for your workflow regardless of the temperature. Our FAQ #087 discusses the effects of cold weather battery issues in detail:

Circuit Boards

Circuit boards can also be damaged by cold, because they expand and contract with temperature fluctuations. Over time, this can cause poor connectivity at the board level. Condensation is another killer for cold electronics in areas with high humidity. When you bring a vented unit into warm, humid air after it has been sitting in the cold, the condensation can be bad enough to cause electrical shorts on circuitry. We have never seen this issue with regard to our products, but that doesn’t mean it couldn’t happen. Do you want to be the first it happens to?


Cables can get stiff and brittle in the cold. They will still work as designed but will be a bit more fragile. Any additional stress on a cable also stresses the wires inside.

6 Ways To Prevent Cold-related Malfunctions:

  1. When you bring equipment out of the environment in which they are stored, do so gradually, so that the display can acclimate to the ambient temperature. A good rule of thumb is to let the unit acclimate for a minimum of 4 hours before turning it on.
  2. To prevent any chance of circuit board damage from condensation or expansion/contraction, again, acclimate gradually.
  3. If your equipment rides in a bag set-up, consider using portable hand warmers (like the type you use in your pockets for winter sports) inside the bag. Place them in proximity to, but not near or touching the unit. Another low-cost insulator is newspaper.
  4. If they’re being used on talent, bundle transmitters between layers of clothing to trap body heat. Do not put them on bare skin, as skin will deposit moisture and oils onto the unit. When it is cold, bodies actually sweat more, not less, in the effort to regulate body temperature.
  5. If your cables are going to be in freezing temperatures for a period of time, avoid excessive flexing if they are already stiff. If you have the budget and find yourself in this situation often (like documentary filmmakers or those that run sound for outdoor events), your best bet is to purchase thicker cables that are made for use in the cold. Loon Audio makes a great coiled cable that is lauded on a few of the sound tech newsgroups.
  6. This last tip is critical: Before going from the outdoors to indoors, put any equipment that has metal parts (recorder, transmitter, mic) into a Ziploc baggie with silica gel pouches while still outside. Close it with as little air as you can (squeeze the excess out before you zip). You can even put the Ziploc into another and close that – it works like an airlock. Bring it inside and let it rest 15-30 minutes before you put it away (remember to remove the batteries). The silica gel will absorb any humidity, preventing it from condensing on the cold metal.


Wire-Lists#6: Preventing Pogo Pin Failure In Your SSM

Social Media WireLists6 300pxAre you having issues with battery drain or inconsistent power in your SSM, in spite of using fresh batteries each time? Are you hearing an odd, intermittent scratch-click that you can’t trace to any of your other equipment? If you’ve checked everything else, the problem might just be a pogo pin.

What is a pogo pin?

A pogo pin, which is a common term for the positive battery spring contact and is used in the design of all electronics using prismatic (square) batteries, is so-called because it acts like a toy pogo stick. Though they look like solid pins if you look into the battery case, pogo pins are two part housings, with an integrated helical spring inside that applies a constant normal force against the back of the contact plate. This spring counteracts any unwanted movement which might cause an intermittent connection with batteries. They’re very small parts – smaller than a pencil lead - that can cause big problems if they malfunction. Pogo failures don’t happen very often with Lectrosonics products, but they can happen. Most maddeningly, if one is the cause of an SSM’s visit to Repair, it’s one of the less obvious, head-scratcher things that can happen. As they say, You learn something new every day. Fortunately, the causes of most pogo pin failures are 99.9% within your control (the other .1% being manufacturer defect).

This photograph shows a pogo failure that ended up being caused by a compressed/bent/jammed pin. Why is this a problem, and what can you do to prevent it?

Lectrosonics pogo pin damaged

The role of pogo pins in electronic devices

First, a short tutorial on prismatic batteries and how they relate to pogo pins:

Prismatic batteries – the square batteries that are used in the SSM and likely more units that we design down the road - have highly compressed cells and are popular in small footprint electronics like ours. They have nickel tabs, shown as small square windows, for contacts, recessed around 1mm from the battery top. Two sample configurations of the many that are possible, showing their relationship to the pogo contacts, are shown below. There isn’t a pogo “standard” as far as configurations. Each battery manufacturer designs their own (Panasonic manufactures custom ones for our SM). Equipment designers,  if they are using off-the-shelf batteries, then design products to utilize the most efficient batteries available that fit the need.

Lectrosonics pogo pin diagram

The battery contacts that are built into the equipment need to have sufficient travel to penetrate the recess and apply sufficient contact pressure to minimize contact resistance. Resistance, for those of you who are unfamiliar with the mechanics of electronics, is the measure of opposition to current flow in an electrical circuit. Minimum travel of 2.5 mm and minimum force of 200 grams are used to create the energy that powers your electronic device and assure reliable performance in high-drain devices. This requires POGO pins that are flexible, but not too flexible. It’s a fine balance.

I think a pogo pin is bent (or I’ve been told that’s the case)! What happened?

An easy way to check for a damaged pogo pin in an SSM is to lightly – very lightly – press on it with a Q-tip or the eraser end of a mechanical pencil. If you apply slight pressure to the head, you should feel it compress. If the pin doesn’t move at all, it’s confirmation that it is damaged and needs to be repaired. If you hear an intermittent slight scratch or click that you can’t trace back to anything else, it may also be a pogo pin, trying to expand and contract and getting stuck.

Pogo pins can be damaged in the following ways:

1. Putting batteries in the wrong way. This is the reason why we engrave battery direction on our housings and are so explicit in how we explain battery installation in our manuals – because inserting batteries incorrectly can damage these delicate pins.

2. Corrosion damaged the pin. The most common way that this can happen is from sweat. And it’s why we are so insistent on using a covering of some kind for high-moisture applications. Once the moisture gets in, you can’t get it out!

3. Incorrect cleaning. This can also cause damage and corrosion. Never spray any type of contact cleaner or petroleum-based solvents (such as WD-40) directly onto pins. Instead, apply a small amount onto a Q-tip or paste brush and apply only to the contact pins while holding the unit upside down. This will prevent liquid from seeping inside.

Don’t be one of less than a dozen annual SSM pogo pin failure cases! Follow the steps here and you’ll be good to go for years to come.

Wire-Lists#5: 4 Ways to Mangle Your Mic

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We think of lavaliere mics as being indestructible because they’re self-contained, but the fact is that some seemingly innocuous things can wreak havoc on them. And you often won’t realize that you have a faulty lav until you listen to your recorded tracks and realize that they just don’t sound right (talk about wasted time!). Here are 4 ways that you can mangle your mic:

  1. Keeping the mic attached to the transmitter it’s being used on, and wrapping it around the unit body when you’re finished. This is a BIG no-no. Over time, doing this can weaken the inner threads of the wire, or worse, break the 5-pin connector. There is no inexpensive fix for these if they happen. Disconnect your lav when you’re finished with your project and store it in its case.
  2. Allowing the lav to come in direct contact with skin. We realize that you want to hide the lav on camera if possible, and the easiest way to do that is underneath clothing. It is best to keep a layer of fabric between the lav cord and talent’s skin, for the simple reason that sweat is corrosive. Lav wire encasements are slightly porous, and over time, sweat can leech inside, corroding the copper wires underneath. Like wrap damage, there is no easy fix for this.

Wire-Lists#4: SM Transmitter Cleaning – Tips for Battery Doors and 5-Pin Jacks

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SM transmitters might go through hell on the job --  but they don’t have to look like it.  Battery doors and the 5-pin jacks are particularly susceptible to wear and tear. These tips can help:

Battery Doors

IMG 3410If the battery door and mating surface on your SM series transmitter look like this and are starting to become difficult to open, don’t scrub them with an abrasive!  We’ve seen a few units that were damaged by steel wool, sandpaper and other materials. Multiple problems can be created as a result, such as getting particulate (tiny pieces that break off) into the unit, damaging the battery contacts on the door, and removing the conductive coating from this area and even the entire housing. 

IMG 3411To clean, we recommend Wright’s Silver Cream (available in Walmart and Home Depot; under $10 for a small container that will last you a year or more) to clean the door and housing. 

Using a small amount of cream, allow to dry and then GENTLY clean the cream from the door and housing. If excessive force is used when removing the dried cream, the conductive finish can be removed along with it.

Removing the thumbscrew from the door can make cleaning easier, though it should be done in a specific manner. Instructions on how to properly do that can be found here. Please keep an eye on the e-clip and washer which, if either are lost, damaged or replaced incorrectly,  can cause the thumbscrew to not seat properly in the case and cause wear to both the door and mating surface.

Your end result after cleaning with the cream will look like this:

IMG 3412

The 5 Pin Microphone Jack Opening

The 5 pin opening and contacts for microphones on SMs can likewise collect grease and dirt. You might think that an easy fix for this would be to use a contact cleaner such as WD-40, Goo Gone or acetone, but there are two potential problems with this idea:

  1. Any type of liquid can seep into the unit under surface mount parts and thru-holes and build up on the circuit boards. We don’t want to tell you how many units we have gotten in due to this type of “cleaning”…or how many of those transmitters ended up being a lost cause.
  2. The labeling on many contact cleaners will read something like “compatible with most plastics, paints and rubber surfaces.” The problem is that the labeling is not specific enough. Which plastics, paints or rubber surfaces? Theoretically, you could clean the battery contact and the 5-pin, but there is nothing keeping the liquid out of the unit.

So how do you clean the 5-pin jack?

First, you can try canned air. You probably have some lying around (if not, it’s inexpensive) and it will blow out any dust or lint-like particles inside. If that doesn’t work, you can do what we do here.  We clean it using alcohol and an acid brush (used to apply paste flux for soldering; cost under a dollar and available in any hardware or home improvement store, often in multi-packs), while holding the unit upside down to keep the contaminants out of the transmitter.

Alcohol and brush  Cleaning with the brush 

All of these suggestions will can go a long way in ensuring that they not only work well and stay out of Repair, but look like new, longer. 


Wire-Lists#3: Lessons On Battery Care For The Long Ranger

Social Media WireLists3The Long Ranger Wireless PA has been in the field for over 30 years and remains popular with school marching bands. Every fall after summer break, and again after winter break, like clockwork, we see a fleet of Long Rangers coming in for service with easily-preventable battery-related issues. And in case you were wondering, premature battery failure is not covered by warranty. Here are five things to consider to make sure that your Long Ranger is ready for another semester:

  1. At the end of each use and especially before extended breaks, store your Long Ranger in a safe, dry place that is ideally under 77°F. At 77°F, Long Ranger batteries are estimated to last about 5 years (3 years with the Long Ranger IV) with regular charges. For every 15°F rise in temperature, battery lifespan is cut by 50%. We know that some of you live in warmer climates; our temperature suggestions do not apply to operating environment.
  2. As a best practice, charge the batteries before putting the unit away; and again every 30 days if left unused.
  3. Never allow the batteries to completely run down. This is the best way to ensure long battery life and prevent premature failure. The 12-volt lead-acid battery should last for 6-8 hours during normal-use conditions.
  4. If the batteries have completely run down, don’t give up right away - they may be able to be saved. In the LRIV, an almost-new 12-volt battery that appears to be “dead” can possibly be saved by prolonged charging – up to ten days. And don’t worry, all Lectrosonics equipment contains circuitry that prevents over-charging.
  5. If you decide to change the battery in your Long Ranger, refer to Tech Note 1012 ( or Tech Note 1021 ( depending on which battery you currently have installed. We no longer use the individual 6-volt batteries at the factory, however you may be able to source them locally. To convert the battery from two 6v to one 12v, you should refer to Service Note 1001 ( These Tech Notes cover important removal and replacement tips. For example, a battery pack connected backwards will result in costly damage. During factory service on all Longer Ranger models, a new 12-volt battery is included with your repair fee.


Wire-Lists#2: My Transmitter Doesn’t Work! Three Things To Check

Social Media WireLists2One of the most common calls that we get in Customer Service is that a transmitter “doesn’t work.” Since “doesn’t work” is a very broad complaint, there are four things that you should check, prior to calling us, that could help you self-troubleshoot and possibly eliminate the need for a call altogether:

  1. Do your transmitter and receiver both have power? While it sounds rudimentary, ensure that your units are plugged in or that your batteries are fresh. Bad or weak batteries are surprisingly common. A general rule is to store your units between use without batteries, and supply new or freshly charged batteries at the start of each session. And make sure your batteries are inserted correctly – it’s easy to put them in the wrong way. All of our units are marked with battery orientation somewhere – either on the back or side of the unit, or inside the battery compartment. You may also need check your power supply, battery eliminator or BDS unit for proper voltages.
  2. Are your transmitter and receiver on the same block and are they tuned to the same frequency? These two discrepancies account for a great number of the calls that we receive. Additionally, if you’re trying to synch a transmitter and a receiver in the 486.400 – 495.600 MHz range of Band A1 and things are not working, it’s possible that you are running into the Block 470/19 overlap. For things to work in this situation and enable the correct pilot tone, your block and hex codes must match. Because of the unique design of the Lectrosonics products, each frequency within a block has a different pilot tone. This helps prevent unwanted un-squelching when an intermod lands on a receiver channel. However, the overlap between blocks 470 and 19 within the A1 band means you can have the correct frequency but since the transmitter and receivers are set to different blocks, the pilot tones don’t match. Be sure to check both the frequency AND the block if you are in Band A1 but are not getting audio.
  3. Are your transmitter and receiver on the same compatibility mode? Like frequency and block, if two different modes are selected, the units will be unable to communicate, or you may have audio distortion. Like people speaking languages, they both need to be using the same one in order to understand each other.

We hope that your issues are solved with one of these four checks. If not? Give us a call at 800-821-1121. We’re here Monday to Friday, 8 to 5 Mountain Time.

-The Lectrosonics Parts & Repair Team

Wire-Lists#1: The 4 Don’ts for Preventing Sick Transmitters

Corroded board

Nothing is more frustrating than turning on your transmitter…and…finding out it doesn’t work. Like with winter colds, sick transmitters can take some diagnostics to figure out and cure. Here are 4 suggestions to help prevent problems before they start:

1. Don’t place the transmitter against bare skin. All transmitters are susceptible to becoming damaged from moisture, including sweat (and everyone sweats). Sweat is a carrier for water, salt and oils which can leech into the transmitter and corrode the circuit boards and other parts. Once sweat or other moisture seeps inside the unit, there is no wiping or removing it. So how do you prevent this? By placing the transmitter into a pocket, pouch or baggie; or (best option) using one of our specially-designed silicone covers. Pro tip: keeping transmitters – and especially their antennas – away from skin also improves RF transmission, bodies are mostly water and water absorbs RF.

2. Don’t leave batteries in an unused transmitter. Best practice is to remove them when you are done with a project or a job and replace them with fresh ones when the unit is used again. At best, batteries that are not powered up can lose charge over time. At worst, they can corrode or leak, thereby irreparably damaging your unit. In general, we recommend that you use fresh batteries for each job, performance, sermon or gig. Because our units provide very high-performance RF and audio, they do use a fair amount of current. New or freshly charged batteries are part of the formula for success.

3. Don’t wrap cords or mic cables around your transmitter when it is not being used. Over time, this practice will damage the cord. Mic cords cannot be repaired or replaced if damaged. Disengage the mic and wrap it loosely to prevent pinching or kinks. Most lav mic manufacturers provide a pouch or small plastic box for storage. If yours didn’t come with anything, we sell our MICBOX (sold with our lav mics) and our small zippered pouch, part #35939 (sold with the HM172 headset microphone) separately, for a reasonable cost.

Corroded housing4. Don’t trust the repairs! We don’t mean this literally, of course! When a unit is repaired and returned to you, immediately power it up and test it. Ensure that it works properly before storing it. Each unit that we repair has a 90-day warranty on the repairs. We need to know sooner rather than later that the repair wasn’t adequate, so we can then correct it under warranty. Sometimes, we learn that users have received a unit back from repair, then stored it for months until the next time they need to do a job, when they discover that it doesn’t work properly. This is rare, but it does happen.

Our products have reputations for withstanding heavy demands over a long lifetime, and the care you give them goes a long way in keeping them in peak performance.

- The Lectrosonics Service & Repair Team