SOT: looking for good cordless phone sets

Do you mean four independent lines?

I purchased a refurbished Panasonic KX-TG4000B 4-line base + KX-TGA400B cordless handsets several years ago on eBay which as best I can tell, meet all of your requirements except $100 price. The handsets have a jack for headset.

They have worked very well. None have needed repair and the original batteries are still fine. The handsets have excellent range in my limited experience with phones.. I can put the base where ever I want in our 4,000 sq foot home with no significant reception issues. This model has doubtless been superceded, but at your price point of ~ $25/phone (right, ?) , you might be needing to look at other than brand new items.

... Marc Marc_F_Hult

Sorry... 3 or 4 handsets all attached to 1 phone line.

Multiple line capability might be nice if we get something that hooks our cell phones in as a second line.... but i realize that'll drive the cost up.... and it's certainly not an immediate need.

It uses standard rechargeable batteries?! Sweet... Maybe other panasonics do as well. (Custom batteries is a personal gripe of mine... I love that the OLPC program uses C cells in it's $100 laptop)

That panasonic looks like a 2.4 unit.... so it might conflict with microwave and 802.11b/g/n(?). Any problems?

That's about right... $25-35 a phone.... The only one line makes that a resonable price for new even. (heck we don't even need/have caller ID...)

Looks like the "multiple handsets talking at once" is called "conference call" on most of the advertisements. What i want is say for my wife and me to be able to talk to a person on the phone at the same time, each from a handset.

So why do they need to be coordinated? Just get four cordless phones. For example, we also have an even older KX -TG210 2.4 ghz 1-line cordless connected to the main line in parallel to the 4-line phone.

I used something called a "Cell Socket" for a while. I plan to put up on my "porch sale". But it requires one a few specific Nokia phones to work.

Oops .. no. But we never have any problem with running out of charge either. If we did, we would just pick up another extension (after fiddling with the forwarding).

You can't use it within 8-10 feet of the microwave, but otherwise have not had problems.

Then why not just get four cordless phones? They don't need to be coordinated or part of a set. Just wire them in parallel or daisy chain.

... Marc Marc_F_Hult

blast! that would have been a big one.

Convenience/elegance/power usage/space considerations...

I'd rather not deal with 4 base units at one location with the phone jack. Also, we'd rather have the phone unit chargers where they are typically used, hung up most of the time. Those locations don't have phone jacks, thus the desire for 1 base unit, with remote charging stations for at least 2 other phones. Also, 1 basestation means that the phones are less likely to interfere with each other... at least you'd like to think the people making it would design it so. Finally, not a listed requirement, but being able to page the other handset is a "good thing", and that's practically a given with multi-unit sets, which is why i didn't originally list that as a requirement.... my bad.

Thanks for your suggestions though!

I just bought a 3 unit Uniden 5.8MHz set from Walmart for $72 and my only regret is that I didn't buy 2 for that price! Model number was TRU-9480-3 and it normally sells for $100.

Yes! Set comes with a base station, 3 handsets and two handset chargers. Box says it supports up to 10 handsets.

Yes.

Yes.

Do you mean two units talking to each other while the third is on a phone call or are you talking about a two-line cordless phone or are you talking about two basestations operating simultaneously or conference calling between all handsets simultaneously? I know you can you can use one set as a baby monitor and still receive calls on the monitoring set but I haven't tested the conference features.

That's gonna be hard to find. This unit takes a 3 AAA cell NiMH pack with a small two pin connector. Easily replaced if you have a source of AAA soldertab cells and a soldering iron.

Finally, I have a cordless that doesn't "hear" the microwave or tear up the wireless cam picture. The sound quality is remarkable. The phones can be used a speakerphones as well as baby monitors. You can also activate the recorder remotely while on a call to record directions, phone numbers, death threats, etc. (-: I get clear reception in every corner of the house and when the ice clears, I'll check the outdoor range as well.

None that I can see but if it's non-volatile RAM, it's less of an issue than it could be. I keep mine plugged into a UPS to provide phone service during brownouts. Not sure how long it will power the unit, but I'll keep an eye on it during the next power outage.

Cordless base, no antenna on the handset to gore you when you bend over with the belt clip on, a handset locator, LED 'number of calls indicator,' belt clips, 100 number phonebook, wall holders, nice bright orange backlit LCD display that shows name AND number simultaneously, great voice mail capabilities (envelope icon on handset connects with base and plays back voicemail through the speakerphone with nice clarity) and other neat features like being able to assign special ringtones to specific callers based on CID.

Worst problem? No keyboard "lock out" so that if you have it clipped to your belt and bump into something, it's very likely to try to dial out. )-: You'd think in this day and age that a keyboard lock would be universal but it isn't! I'm gonna have to make a "dial proof" holster.

-- Bobby G.

There's usually a small circuit board tucked between the NiMH cells with a thermistor and a few other components to limit the charging rate. You'll need to salvage it from the old pack (unless it's the reason the old pack died). The thermistor needs to sense the temperature of the charging NiMH cells - that's why it's nestled amongst them.

UnidenDirect has refurbed units but even those cost far more than you paid.

I have 2.4GHz units but I seldom use the microwave while on the phone and am never in more than one room at once so I cannot comment on interference or conferencing.

I'm not sure this pack has anything but batteries. Since it's still under warranty, I am not slicing it open to see! There's a thin plastic wrap over the three batteries and I can trace the wiring and the solder tabs with my finger and I don't see (actually it's more like feeling) any other components. It takes 20 hours to charge so I am assuming it's very low current trickle.

I recently discovered that LIon batteries absolutely need thermal and voltage monitoring during charging because they will overload and explode when left on unsupervised trickle charge. But I thought NiMh could safely trickle charge without any detection hardware on the pack. My NiMH AA and AAA sized standalone chargers I have (except for a 15 quick charger) don't monitor temperature, they just monitor charging voltage. The LIon chargers that I just bought for CR123 and CRV3 photo-type batteries both have "fingers" that contact the battery at its midpoint. While I haven't opened them to inspect them, I assume that finger is there to make sure the charger shuts off if the battery gets too hot. None of my NiMH chargers have fingers except for the quick chargers.

As you point out, I will be careful to insure that if there are any components in the old battery pack, they get transferred to the new one, should I decide to build my own. I suspect that Walmart will be selling replacement battery packs for little more than what it would cost me in time and effort to build one. I'm actually quite happy that Uniden is using NiMH batteries. Lots of consumer crap still comes with NiCads and their infamous memory problem.

I wasn't really in the market for new phones but when I saw a package that came with a base station and a total of three handsets for $72, I couldn't resist. I just hope they are still on sale today when I go back because I could use another three handsets and a spare base at less than $20 a handset!

(-: I have some 2.4GHz wireless cams that would not work at all when near my Panny 2.4GHZ phone (which apparently has a 900MHz return channel!!) and the phone would cut out or get scratchy at the ends of the house. The

-- Bobby G.

Typically the thermistor and thermal switch are very small and not obvious - they may even be inline. Here's a Panasonic app note...

You're right. On the first pack that I examined, it was not possible to see the small components as they were tucked in the "void" created by the wrap bridging two cylindrical objects. I looked at other packs, and the thermal protectors were quite visible because they were not nestled in the groove between cells, but right up against the cell. (Anyone remember that SNL "Superman in WWII" skit?") Still, if you weren't looking hard, they'd look like a solder joint. Remarkable.

So how do the plug-in AA chargers avoid thermal monitoring or am I just not seeing those thermal detectors/protectors either? I have *lots* of those that I'm willing to cut open because I own a Nikon Coolpix battery hog camera that only runs well on nearly-new NiMh's. Lots of hi-cap NiMH cells came with free chargers so I have a box full.

I've finally settled on one make and model of charger because it both detects bad cells AND chargers any assortment of any type of AA or AAA cell, even one at time. More importantly, it never seems to ruin cells by overcharging them. That would lead me to believe that it does sense temperature because it keeps the cells pretty warm but never as hot as other chargers do.

While I am too lazy to get up and look, FWIW, I believe it's an ULTRA Rapid Charger and it came with a lifetime guarantee (mine or the company's I wonder?) that would probably be voided if I looked for a thermistor. I suppose it wouldn't have to actually touch the battery. To look or not to look? Hmmmm .......

-- Bobby G.

FWIW, none of the battery packs that came with the Panasonic KX-TG4000B

The ones I have consist simply in five Ni-Cad, two Ni-MH , and three Ni-MH AAA batteries (respectively) connected in series with welded stainless conductors.

These are available from many different manufacturers. For example the two-cell Panasonic HHR-P506 pack used in the Panasonic KX-TGA400B handset is also available from Energizer (ER-P506), Uniden (BT-904), JASCO (GE-TL26602), Lenmar (CBC206), AT&T (17F) as well as generic 'brands" and can e purchased for less than $5 + shipping or $8 shipping included.

The diagram that Dave references is used in three 3-wire battery packs that use additional, often external electronics in conjunction with an on-board thermistor which is used as a sensor and is not "inline". In large packs, (eg laptop computers) the active electronics (an IC) may be in the battery packs themselves. Years ago I saw battery packs with simple built-in positive temperature coefficient thermistors which were used in line (in series) as over-temperature and(or) over-current protection, i.e., not as a sensing element used with additional electronics. They may still be used. I dunno. But these ain't them.

... Marc Marc_F_Hult

I'm not an expert but there are several methods for recharging NiMH cells. Google on "NiMH thermistor" and you'll find app notes from various chip manufacturers (e.g. Linear, Maxim) that provide details on their dedicated chips.

When higher capacity NiMH cells appeared a few years ago there was a guy on the RemoteCentral forums who proposed manufacturing higher capacity battery packs for the Prontos. I researched it and pointed him to the resettable thermal fuses and thermistor he needed. (He had thought the thermistor in his original battery pack was a diode as it used the same DO-41 glass case.) Interestingly, he found he needed to sell the battery packs for about $15.

While I have a Sony BC-CS2A charger for the individual cells I use in my camera I've never taken it apart (it's not readily apparent how to open it) to see which method it uses. It's limited to NiMH cells. There's a small aperature that might have a temperature sensor behind it. I found specs on a different Sony NiMH charger (Sony BCG-34HRMD) that says it monitors voltage and temperature.

I'm looking for an inexpensive combo NiMH & Alkaline charger.

I think I found one...

I have a Sony BCG-34HC that I just took apart. It had tamperproof slotted screws securing the case. If other manufacturers are any indicator, they've probably gone to some sort of press-fit assembly method. The tamperproof screws tell me they don't want people going in there!

Anyway, on the circuit board, there are two components directly mid-center of each of the two battery compartments labelled RT1 and RT2. They are glassy looking and pinch at the center like an hour glass. Dead center on the board is a yellow something labelled Y1 that looks like a ceramic capacitor, at has markings that look like a tiny copyright symbol and the lettering 8.00S. Both components are far away from other circuitry. I suspect the RT1/2's are the thermal detectors/protectors. Not sure what the Y1 is doing there, but I assume it's an oscillator of some sort if they're using standard board markings.

-- Bobby G.

And on another subject, today's WashPost had an article on greenhouse gases that talked about dirty coal-fired plants:

"A committee of more than 100 experts from the Intergovernmental Panel on Climate Change concluded in 2005 that carbon sequestration has "considerable potential" to help reduce greenhouse gases, and a lengthy study at Weyburn by the International Energy Agency found virtually no leakage. The British Columbia government this month announced that all its coal-fired electric plants will be required to utilize carbon sequestration to eliminate greenhouse gas emissions."

It sure makes more sense to cap the CO2 at the source, rather than way downstream. Trying to modify 100 years of consumer behavior via fiat would have a minimal impact, at best, on the problem.

-- Bobby G.

I read the article this morning. My view has always been that the payback is higher the higher up the food chain you work.

Only 1/3 of the energy in coal gets converted to electricity so any improvement in conversion efficiency gives more power with no increase in emissions. If you combine higher efficiency with sequestration it's even better. That makes a lot more sense than looking for a few tenths of a percent reduction by replacing all residential incandescents with CFLs.

This site might be slightly biased but...

AA NiMH have proved to be quite good in my opinion, although I still carry a just-in-case set of lithiums for my SB flashes.

Nikon F2's through N100 used AA's but my D200 uses a proprietary battery that isn't even the same as the D100 which looks identical. But the the new flash still uses AA's.

So upshot was that on a recent trip long I had to drag along 8 (eight!) different chargers for cameras, flashes, laptops, external drives and so on. I've begun to reject things that can't be powered by standard supplies.

One space-saving strategy is to use charger bases that use the same power supply. One can get 12vdc-input chargers for Nikon, Olympus, AA, AAA, and other batteries and so cut down on the bulk and weight. These can also be used with cigarette lighter supplies in cars.

IMO, wall warts are problem enough when they are on the wall, but even worse when you have a carry an armful on foot through the no-man's land at the border between Jordan and Israel. To boot, the inspectors wanted to inspect it all ...

The search for methods of carbon sequestration to mitigate climate change goes back to at least the late 1970's (at least that's when I first became aware of it). They have had a rocky history in part because they typically involve geo-enginneered solutions which were long considered by many to be dangerous meddling with earth systems.

The second sentence is a non-sequitur, right?

The first of the three conservation R's is to _Reduce_. Modification of consumer behaviour that has been ongoing in the US since at least 1992 with respect to lighting -- long before the currrent crop of pundits knew that their behaviour was being changed ;-) What is never created does not need to be sequestered ("capped") , so reducing demand is a key step.

Most (all?) folks that have studied the problem seriously would flat-out disagree with your statement that changing consumer behaviour by fiat has a minimal effect. Many energy standards are indeed legally binding commands or decisions (i.e., fiats). Indeed, voluntary measures are what have not worked.

The "Fiat Lux" of Genesis was reportedly not originally pronounced as an optional extra or part of a consumer preference poll ...

"LET THERE please BE efficient, inexpensive, quiet, dimmable, full-spectrum, PLC-friendly, union-made LIGHT bulbs that last a long time when used base-down" does seem to be more of a self-indulgent consumer wish-list than fiat.

... Marc Marc_F_Hult

It's an industrial con game. If they can convince us *we're* the problem then they don't have to endanger quarterly profits by investing in recovery equipment. A country like ours, locked into only how well a company did in the last quarter, is so near-sighted that "big picture" items like global warming become a terrible threat to corporations. There was an article in the WP about how a teacher's assn. refused free DVD's of "An Inconvenient Truth" because it might endanger the money they received from the oil companies. Just like Joe Camel and Big Tobacco, Big Oil knows they got to get 'em young to poison their minds.

The big three automakers took a similar approach to both gas mileage and safety improvements and then reacted like stunned mullets when people flocked to imports that ranked well in crash tests and mileage tests. After a decade or two of trying to punish the consumer for forcing all those safety laws on them, they got the picture. Mostly.

To keep this on topic, I've decided that I am going to call my own number as a poor man's "key lock." This way, if I bump into any walls and hit redial, I will only get a busy signal. A pain, but not much harder than activating the keylock on my cellphone.

-- Bobby G.