I'm using rechargable 9V NiMh 260 mAh batteries...

I'm hoping that's a typo and that you meant 2600 mAh.
It could be the brand you're using.
Browse through the archives of the RAMPS (Rec Arts Movies Production Sound) newsgroup for their brand recommendations as, in the past few years, most of these folks have switched exclusively to rechargeables.
Greg (Goji), these folks do "mission critical productions" every day so I'd take their word on what's good and not good.

Mike

Thanks guys,
I'm hoping that's a typo and that you meant 2600 mAh.
No...uhhh....it says 260....I bought them at batteries only
I'll check out the link rs but you are saying that batteries could be the problem (ie intemitent short dropouts as opposed to just quitting)?
Thanks again guys,
Randy

Randy, when I followed your link, it said the brand was " IpowerUS".
If that's the case, then you need to contact them directly (contact info on their web site - ask for Richard) as they, infortunately, have had the odd batch of bad ones.
The good news is that they've been very quick about helping end users.
This issue has been discussed at length on the RAMPS group.

Mike

Thanks Mike,
This may indeed be the problem since Richard stated on the RAMP site that the larger size was an older model battery (mine will just barely fit into the transmitter and receiver) and that he would exchange them free of charge...so I just emailed him...thanks again Mike!
Randy

couple of things about the G1's

ALWAYS use fresh batteries. Alkalines are better, but i use 850mha powertech ones which last a lil over an hour, maybe 90minutes

Ive had my units for a lil over 5 years now.. prolly 6 actually and knock on wood, ive never had a problem, in fact i find them more receptive than the g2's with a longer range and a far more stable tune.
G2s are great for battery life though.

If G1s go bad, its usually a tuning calibration issue, or a simple knockabout. In my case, ive got 3 kits in a small bag, loose.. and theyve seen teh wars let me tell you...

great unit, and prefer G1s over G2s any time of the day

I must be missing something. Can't you just put fresh alkaline batteries into the unit and tell, pretty much right away, whether that cures the problem? That's what I'd do.

Most common problem by far on both the old and new style Sennheisers is the 1/8" locking TRS plug which get stressed in normal use. The first symptom is intermittent audio dropouts. I keep a handful of replacements in my kit and normally replace one or two every run. The metal replacements I am using now have held up without failure. I put an inch-long piece of heat-shrink over the outer cable insulation at the connector for added strength and strain relief.
Look for the Calrad 30-296-BK online.

260mAH is enough to power the transmitter, but I always use fresh alkalines because they'll last 5-6 hours continuous. I've never seen rechargeables come anywhere close to that. That's important because we pay the venue $85/hr for rehearsal time and the last thing we want to do is stop to change batteries. For shows, the extra life is peace of mind.

Part of the problem is that 9V NiMH batteries mostly aren't 9V and a lot of kit will not work at the reduced voltage or not work for very long at all. You can get a "9V" NiMH battery that has an extra cell that I believe will run the Senny kit for a long time.

We have around 7 G2 500 kits for rent and run them off 2,900 mAH NiMH batteries without issue. The stock mike is tragic, replace them with a Gold mic (+$500) and then you've got a rock solid piece of gear. The Gold mics have kevlar reinforced leads and you could probably garrot talent with the lead and the thing would still work. Check the 3.5mm sockets on both the xmitter and receivers, the locking nut can work loose. In general set input sensitivity to -10dB, that'll avoid any risk of overloading the xmitter. If you know for certain the talent will not shout or walk in front of foldback speakers then set to 0dB

One other tip. High capacity NiMH batteries self discharge fairly quickly. If you need batteries that'll be usable after a month in the kit bag, drop down to some of the 2,100mAH varieties.

If you don't use a lot of batteries rechargeables become a PIA, just stick with good alkaline batteries. However be careful of the expensive Oxygen batteries, at 1.8V / cell not everything is happy with them.

Bob.

If you don't mind paying a little extra, consider a 9V Lithium battery. No problem with self-discharge (shelf life of ten years), and about 3-4x the operating time of alkaline.

** ...and about 3-4x the operating time of alkaline.**

So, given a 2-1/2 hour show and a $9.99 battery, can you tell me just when it is going to fail? During the 6th show, or the 8th, or just when should I replace it to avoid a fatal error? How am I going to track just how long each mic was left on during each night of the run?

For my purposes, one $0.99 alkaline 9V Duracell Procell per mic, per show is just the right choice. Talking about "mission critical," this is what surgeons use, and I haven't found a better choice for reliability, either. And, as collateral I've got tons of 8.5+ volt leftovers for those dozens of "noncritical" rehearsals before we move into the venue. My point is, whether it is a surgical procedure, a stage production, a wedding, or a family picnic, battery failure isn't something you are ever going to want to leave to chance. Just my point of view.

So, given a 2-1/2 hour show and a $9.99 battery, can you tell me just when it is going to fail? During the 6th show, or the 8th, or just when should I replace it to avoid a fatal error?

My answer? After each show. It's an extra cost for extra insurance.

Against what?

Against shelf life depletion. Against the possibility that a shoot goes long. Against the possibility that you DO forget on some occasions to replace the battery before the shoot starts.

My biggest problem with batteries is grabbing one that should be good, only to find out too late that it isn't.

But, I agree that going with a fresh alkaline battery each time is pretty hard to beat, so I'm certainly not going to argue the point very much.

The only downside on that approach -- and this is sort of the opposite side of your argument -- is what do you do with all those batteries that still have 70-80% of their life remaining? It kills me (and the environment) to put them in the dumpster "before their time."

[Edit] Oops, you did provide an answer to my question: rehearsals. Sorry, missed that.

OK, now you've got my curiosity going. Sometime this summer, I'll put a lithium in one of our mics during an all-day rehearsal and see how long it lasts. There may be some situations like a dramathon or documentary shoot where the extra life outweighs the extra cost.

For most of the shows and concerts we produce, however, five hours from an alkaline is more than enough and the most economical, given the unpredictability of rechargeables and the high relative cost of lithium.

We typically run 12 or more wireless mics at each performance, so cost is a big factor. 150+ batteries per run is not uncommon, so as rechargeable technology gets better, it will be worth taking another look at.

Thanks to everyone for all the info!
DJPadre said: If G1s go bad, its usually a tuning calibration issue, or a simple knockabout....
Something like this was my first concern because I bought this unit used and was thinking if the problem was a weak battery it would just quit working (or that the dropout would at least be longer than a fraction of a second).

Johnmeyer said: I must be missing something. Can't you just put fresh alkaline batteries into the unit and tell, pretty much right away, whether that cures the problem? That's what I'd do.

I've only used this lav on 2 projects so far; the first being 3 interviews (only about 10 minutes each) and the second being 5 interviews that were about the same duration (BTW on all of these except for that last interview I used headphones to monitor and it happened to be the one I had the dropouts on ).
That said this very last 5th interview was done on the morning after the first four and I recharged all four batteries overnight and grabbed two for that last interview. One of them very well could have been a battery that I had not used until then and be the culprit (fingers crossed)???
As per Mike's suggestion above I went to the RAMP site and found out that indeed this brand of rechargables had an issue with the first models (as identified by their slightly larger size).
The company gladly traded them out for the newer model...so I have emailed the company to see if I can exchange all four of mine.
I have another bunch of interviews coming up in about a week so I'll just use disposables for that one....and monitor with headphones!!!!

Bob : In general set input sensitivity to -10dB, that'll avoid any risk of overloading the xmitter. If you know for certain the talent will not shout or walk in front of foldback speakers then set to 0dB
I did not know the xmitter could overload and cut-out (as opposed to just distort). Now that I think about it the talent started getting louder toward the end (where the dropouts happened) so I checked and the transmitter was set to 0db. I just set it to -10...thanks Bob.

Thanks again guys,
Randy

I know this thread got diverted to a discussion about batteries, and I am equally to blame, but I don't think your problem is being caused by batteries.

See seven posts up. The locking mic plug is the most common cause of audio dropouts with these units. Replacing it with the one I mentioned often cures the problem completely for $5. If you had battery or antenna issues you would notice RF carrier dropouts right away; batteries do not contribute to audio-only dropouts in these units.

The modulation setting will not cause dropouts, only distortion as you suggested. Starting points are -10 for ordinary speech, -20 for actors and singers, and -30 for belters and screamers.

Another thing to check is the squelch. If you can get by with 5db, do so. If RF noise breaks the squelch at 10db with the transmitter off, then you need to pick another frequency. To see if 5db squelch works for you, set it to that level and turn the transmitter on. Then turn the transmitter off. If you hear a windstorm through the headphones as the transmitter powers down, you need a higher squelch setting.

I know this thread got diverted to a discussion about batteries, and I am equally to blame, but I don't think your problem is being caused by batteries.

Thanks musicvid; I didn't respond earlier because after you suggested this I tested it by moving/jiggling the mic plug but there were no dropouts.

Thanks again,
Randy

I've had some that didn't react to wiggling the wire, either. It may be an expansion/contraction thing. In those cases, replacing the plug solved the problem.

While you were posting, I edited my most recent post to include some information about squelch settings in the receiver. It's worth checking as it can cause audio dropouts as well. Hope it helps.

While you were posting, I edited my most recent post to include some information about squelch settings in the receiver. It's worth checking as it can cause audio dropouts as well. Hope it helps.

I don't know much about squelch (works like a noise gate?) but here's what I did: On the receiver the squelch was set at 20db. I changed it to 5 and got a lot of continuous noise when I shut off the transmitter. I tried it at 10 and got the same noise for about 1 second. Should I leave it at 10?
Thanks my friend,
Randy

**On the receiver the squelch was set at 20db.**

I think we're well on the way to solving your problem.
If you get any noise at 10db, it's time to find a new frequency.

1) Look at the back of your unit and find the frequency band:
500+ Mhz = "A" Band
600+ Mhz = "B" Band
700+ Mhz = "C" Band

2) Go to http://www.sennheiserusa.com/findfrequency/default.asp and find some frequencies for your band and locale that are not occupied by a current or future TV station. Sennheiser does a "pretty" good job of keeping these up-to-date.

3) Set the receiver squelch at 0db (important), and with the transmitter off try out some frequencies and look for RF noise on the upper display bar. Pick a frequency that shows little or no RF activity with no squelch. Write down the numbers for a few good frequencies in case you encounter a problem down the road. In the relative quiet of NM you should have no trouble finding several good frequencies.

4) If you are using more than one wireless on the same band, make sure they are both in the same bank for compatibility. This is explained in detail on Sennheiser's site.

5) Once set, set the squelch at 5db and run the squelch test (previous post) again. If necessary you can bump it up to 10db, but no higher.

Barring a mechanical/electronic failure discussed above, I bet this will fix your problem.

Update: I see Sennheiser has changed their site around quite a bit and I can no longer find the stock frequency and bank charts for the older Evolution series.

So, I put them up on my ftp site in case anyone can use them. They are a valuable resource for anyone reconfiguring their G1's around the new DTV stations. (Sorry I can't link these.)

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That should be very helpful musicvid...thanks very much!!
Randy