LarryF

The DPA microdot connector for all our 5 pin UHF transmitters is DAD3056. It has the same wiring as on our site for the pig tail version of the mic. Best, Larry F Lectro

I should have said further that the calls at "five to five" on Friday(!) are called Maxi-Mouse calls. LEF

The calls at "five to five" are called Mouse calls because they always seem to be from a musician who owns a Lectrosonics Mouse Amp from 15 years ago, who has a gig tomorrow and has just discovered that his batteries are dead and he's misplaced his charger. Can we get a charger right out so he can have it tomorrow? We are used to it. ;-) If the phones are still on, we'll answer it and smile. Best, Larry F Lectro

The DPA has a "unique" output stage that likes a fair amount of current to achieve a low output impedance. The circuit is quite clever. The Lectro servo units (SM's, LMa's and UM400a's) can provide much more current than necessary, up to 2000uA. After all, we designed the servo input for the B6 which is another high current electret. The wiring shown for DPA, as I posted earlier, provides 500uA which is a good intermediate current value. We have a 4061 here and it is a fine mic with the Lectro transmitters. We have a number of theater users that like the DPA series and use it regularly. Best, Larry F Lectro

The wiring for Lectro is pretty simple. See figure 3 on this page: http://www.lectrosonics.com/component/option,com_fss/Itemid,81/catid,4/kbartid,10/view,kb/ Best, Larry F Lectro

Here's an FAQ that applies to any system: http://www.lectrosonics.com/component/option,com_fss/catid,-2/view,faq/ Best, Larry F Lectro

Hi Tapio, The Sony camera is deliberately "crippled" to prevent use of the second channel input on the internal connector. The 2nd input is even shown on their schematic but is disabled. I have been told that Sony will void your warranty on the camera if you enable the second channel with a tiny jumper. My feelings are not printable on a family forum. Of course, Panasonic and Icky work well with these receivers. For the Sony, you needed to buy the SRA-5P which feeds the 2nd channel externally. I would think your dealer would give you a trade in on your SRA if it is still in new shape. Best Regards, Larry Fisher Lectrosonics

We have done the rapid prototyping for a first pass mockup and it seems to work well. Drawings are in our machine shop to make the plastic molds. The head of production took several days of vacation (rampant disloyalty) and I don't know when the molds are scheduled to be made and run on the plastic machine. We've got to be getting close. I figure shipping in 30 days. Best, Larry F Lectro

Just a follow up on the previuos posting: Dean in service said, " We don’t normally see the UM400 have battery contact problems that prevent operation. UH400, UCR190, CR187 all had contacts that would bend to the point of not working but not the UM. More likely, in this case, that the processor clock crystal is bad (for whatever reason). Just a guess though, number of issues that could cause this symptom." Best, Larry F Lectro

Hi Ethan, The final finish on the SM's aluminum case is a cracked nickle plating with Teflon forced into the microcracks. We used it to improve assembly tolerances and because it is conductive. With the nickle plating, the negative contact battery door can make electrical contact with the case, completing the circuit. The nickle is pretty tough but will polish when rubbed against other metal. On the belt clip, we kind of like the blue but can change our minds if many others feel the same way. We have requested a possible lit LCD from our vendor but don't know if they can fit it in the available space. Several people have hammered on us about that LCD for years (Scott Farr, you know who you are). Best Regards, Larry Fisher Lectrosonics

The springs are photo etched from stainless steel sheet. The sheets are made by rolling the steel to be thinner and thinner. The direction of the stretching means the metal flows and has a grain direction. This causes the metal to bend easier in one direction than the other. If you form the springs at right angles to the correct direction, the spring bends easily and takes a set. After we have it gold plated, it is hard to see the incorrect grain direction. The fix is to replace the spring. This comes under the usual "We blew it" warranty. Best Regards, Larry Fisher Lectrosonics

Hi Tim, Yes. It will be going to the test lab shortly. My WAG, 3 to 4 months. Best, Larry F Lectro

Hi John, I'm going to put this in a logical decision order. First, we could make the unit smaller if we used a permanent rechargeable battery. We could also use a custom replaceable Li-Ion battery in a rectangular shape, like a cell phone or small camera. We've opted to go with replaceable batteries because common replaceables are available almost everywhere and anytime. Further, you don't need to be near a power source for recharging. Secondly, given the replaceable requirement, there are only two really common batteries that have reasonable costs, good power density and are available at your local Quikie Mart (Thank you. Come again.). These are the rectangular 9 Volt and the AA battery. I have been told that Europeans hate the 9 Volt and also that the AA is more available than the 9 Volt outside the U.S. Another small battery is the AAA but the power density is one third that of a AA. For instance, the AA alkaline works well in moderate power drain applications, the NiMh works well in high drain applications as does the lithium AA. Further the alkaline is one of the cheapest batteries on the market, the NiMh is rechargeable and the lithium is moderately priced with good power capabilities. There are also NiZn AA batteries that are low leakage (long shelf life) and there are very good low leakage NiMh's. The AA battery is almost the same power capacity as a 9 Volt but has smaller volume. Finally, AA batteries are constantly, albeit slowly, being improved. Look at the capacities now and ten years ago. This why new Lectro products will be AA based. Finally, there are no batteries at other voltages, i.e., 3 or 5 Volts, that are commonly available and low cost. Replaceable batteries do add to the unit's size. The batteries take up room themselves but you also have the battery door and contacts. The various power supplies I alluded to in previous posts, take up some room, but a higher voltage battery would only eliminate one or two sections of the supplies. The batteries themselves take up the most room. Designing for the lower European power, would help a little on battery life, but the DSP and other digital circuits are the actual power hogs. However, with interference sources growing like Topsy in the U.S., higher power does seem to be the way to go, with variable power being a good compromise between punching a signal through the crap and battery life. Further, interference is only going to get worse in the U.S. Going to lower power helps some on battery life Below 100 mW, with current DSP designs, lower RF power does not buy any real advantages. If we went back to all analog circuity, reduced RF would then make a difference. Finally, the dual battery SMQv out sells the smaller SMv by almost 3 to 1. Battery life and increased power seems to be of more importance than size. This is not what I guessed a few years ago. Interestingly, the retro UM400a (9 Volt unit), also outsells the smaller SMv. I guess this just shows that users prefer the UM400a black wrinkle finish over the smaller SMv size. Best Regards, Larry Fisher Lectrosonics

Yes, the switcher is in the eliminator and transforms the 12 to 18 Volts to a little less than 1.5 Volts. Then switchers in the SM generate +3.3 Volts from that 1.5 Volts for most circuity, 1.8 Volts for the DSP core, plus and minus 3 Volts for some audio amps and 6 Volts for the limiter. The 6 Volts is regulated to a clean 5 Volts for mic bias and further dropped to 2 or 4 Volts in the servo bias section. Additionally, 4 Volts is generated in another switcher for the output stage at 250 mW, and 3+ Volts for 100 mW operation and less than that for 50 mW operation. Then there are about 4 FETs used as switches to put the SM into sleep mode without turning everything off. Really, there is nothing major inside an SM but power supply stuff. The rest of is just left over Mr. Microphones that we got years ago as surplus. Best Regards, Larry Fisher Lectrosonics

Next NAB. L

Hi Tim, I'm not sure why you are getting different display levels on the two receivers. As far as the reduction in range, try this: start separating items from your bag and testing range differences. First, I'd try just the SRa's by themselves with only the battery power. Then start moving items near the SR's =>ONE<= at a time and see what happens to the range. You can look at the display, but usually by the time you see anything on the display, your range has dropped by a factor of 3. It is possible that RF is coming off the cases or cables of various items and not necessarily from the filtered antenna. Best Regards, Larry Fisher Lectrosonics

We have discussed a redesign down the road. The current packaging is not ideal. Best, Larry F Lectro

Thanks for the good words, John. The input power pin would be pretty easy to do on the older 9 Volt units (just a small linear regulator) but much harder on the SM series since the battery voltages are 1.5 Volts and would require a switcher to drop the external 12 Volts down to 1.5 Volts. We would also need to dedicate another pin to a power ground to keep ground loop currents off the audio ground. The final straw is this: if I even thought about changing the 5 pin connector pin outs, there wouldn't be enough wholesale tar and feathers to meet the demand. It is one of those great ideas that needed to be done from the beginning, like in the previous century. When we change the connector wiring again, slated for 2035, it'll be at the top of the list. Best Regards, Larry Fisher Lectrosonics

Some of the young punks here, that have only been around for ten years, don't have the memory skills of their seniors. ;-) LEF

We have tested the D4T transmitter and the Quadra transmitter next to our receivers and found no detectable bleed. A little more subtle point is we also found there was no induced RF noise in un-bypassed lavalieres or unfiltered audio inputs. The occupied bandwidth is so wide (5 MHz) that there is very little energy at the audio frequencies. On top of that, the modulation method has a relatively low AM component. Best, Larry F Lectro

Hi John, Very cute. If we can help with info in the future, let us know. Cheers, LarryF Lectro

Hi Bob, Great idea. Will work on a Lectro version that will keep the little nylon nubbin that protects the metal plating. Wish we had thought of it. Best, Larry F Lectro

The "a" in LMa added the servo input and the circulator in the output. LEF

It is correct that the LM's did not have isolators; however, the LMa's do. If we had any marketing sense, we'd put the presence of the circulators in our data sheet. So, for all current transmitters and for all planned transmitters, there are circulators (isolators) in the output stages. This also includes the IEM and D4 915 MHz transmitters. Best, Larry F Lectro

Bends in the antenna make very little difference in performance. I just grab the bend between my fingers and bend it in the other direction more and more until it looks straight. If you get too many kinks in it, you can tell the client it's a fractal antenna. Best, Larry F Lectro