Cheap, simple, robust wall mounted phones?

[T i m]

Hi folks,

I was helping my mate today in his greenhouses (warm or what) re re-wiring some old wall mouneed BT (706 I think) type phones but once I'd got them going I found they were pretty shag//// duff. ;-)

So, I looking for a basic cheap and robust wall mounted phone (or 3) that I can put up for him.

I don't think anything fancy would last very long in the heat / cold / humidity.

I did pop into Dixons and they had a couple that might be ok (for

+AKM-6.99 / +AKM-7.99 .. I even showed them how you turn the little bit of plastic round to make the 'hook' to stop the phone falling off when wall mounted! ) but nothing very 'chunky' to be held with gloved dirty hands?

Any ideas?

All the best ..

T i m

[Dave Plowman]

They need some mods to work properly on a modern plug in system.

BT did phones in a waterproof enclosure for this sort of work. You'd probably find them on Ebay.

[Lurch]

On Fri, 02 Apr 2004 23:19:41 +0100, in uk.d-i-y T i m strung together this:

You could always try eBay, there's usually a few old style BT phones on there. I dont think you'll get much more rugged than what they have now these days, not for a greenhouse anyway, to my current, sleepy knowledge at least!

[Harry Bloomfield]

T i m was thinking very hard :

Why mess about with wiring?

DECT phones are quite cheap these days, they cover 100yds from the base and you can carry them in your pocket. They don't generally fit the 'chunky' spec however.

[Sneezy]

T i m wrote in news: [e-mail]:

BT do a big button phone for those with sight problems. Ideal for those with big mits or gloved hands. Pretty certain it's wall mountable. It also has a volume amplifier and fairly loud ring - could come in handy if you have John Innes bunged in your ear holes. :D

[T i m]

Hi guys and thanks for the replies,

I did pull the diagram for the 706 and the bells were disconnected (about the only thing that would need modding to work in a new ststem). The old carbon microphones do go bad over time and are usualy the source of the crackles.

The phones had been using a 2 wire system so when I ran the new wire from the office to the greenhouses I used the new ("new"! ") 4 (3 used) wire cable and extended that through to all the phones and 'parked' the unused wires on spare terminals in the phone. I didn't not what the off-hook voltage was (he's probably a fair way from the exchange) but the on hook was a good 50V.

I was working on the lines that the phones would probably need replacing and would put plug in slave boxes where the phones were now.

I may not fit the bell wire to the box (if you can't turn the ringer off on the phone) as he has big alarm type (BT provided extension bells) bells in the green houses that would drown out any std phones ring in any case and I would try to keep the REN down.

Thanks for the input so far guys .. more options to consider.. ;-)

All the best ..

T i m

[T i m]

Hi Harry .. I just thought about that and I'm not sure how well a wireless phone would work in that environment? He may have tried having the base unit in the office and the (wireless) phone in the greenhouse and had problems? He suggested I went outside the greenhouse to improve cel phone reception (but that could have just been the location in general).

He does have some fairly chunky electrical gear in there (auto feed systems / computer / pumps etc) that might interfere with his old analogue cordless phone but a DECT might be ok?

I might take one up there and give it a try (but there may be a reason why that can't be used ..)

Oh, and I thing the greenhouse is longer than 100 yds but if it was in the middle ...

All the best ..

T i m

[T i m]

Hi and good point re the ruggedness.

Maybe a new carbon mike insert will make them useable. He only needs to answer calls on the greenhouse phones to save him going from the hot greenhouse to the cold office (and he is 71!).

All the best ..

T i m

[Dave Plowman]

Some phones will have been modded with high impedance bells - BT did do this. But a resistor in series works well enough.

A few thumps on the palm of the hand often sorts them.

[T i m]

He doesn't need the bells Dave as inside the greehouse are two large extension bells. With pulse dial you do get a timy bit of tinkle on the large bells but he would rarely (if ever) dial out from these phones. An MF phone would cure all but that on/off hook 'ding' ;-)

I tried that ..(and a few taps with a screwdriver handle) but they were still pretty grim. It was suggested these phones could have been in the greenhouse for over 20 years!

All the best ..

T i m

[Dave Plowman]

The bell tinkle is down to incorrect strapping within the phone - I've got an 'idiot' sheet with the mods to make an old phone work on the new system somewhere, which I could scan if you'd like. It's easy enough on reasonably recent old phones - you just alter links inside.

Right. If you can't find the correct old BT type in a waterproof box (with a picture of a handset on the outside) I'd think any IP rated box with a hinged lid would do. Although unless actually being soaked in water, I'd think a normal phone should survive ok - given that plenty of countries have very high humidity at certain times of the year. Unless you're growing plants from another planet. ;-)

[Harry Bloomfield]

T i m used his keyboard to write :

The (metal?) framing of the greenhouses will make little if any difference to the 2.4Ghz DECT signal, it will happily go through the glass. We only loose the signal when there are lots of house walls between base and phone.

Bet it doesn't compare to the chunky electical gear here ;-)

DECT is a very proposition to the old analogue portable phones. The range is much greater and the audio perfectly clear right up to the very limit of the range. The old analogue units can also be easily eaves dropped upon and calls made free at your cost, but not with the digital (DECT) ones.

If necessary, the range can be extended several times over using DECT repeaters, although I certainly don't think this would be necessary in your case.

[T i m]

Fair enough .. I believe the actual framework is wood but the place is riddled with cables , suspension cables and plumbing potentially creating some interesting waveguides etc in there?

We only loose the signal when there are lots of house walls

True. for most of the time it would be nearly 'line-of-sight' between a base inside the greenhouse and a DECT phone in his pocket or on his belt etc. Unles a few thousand tomato plants in the way also count?

I bet .. talking if that .. do you know anyone that would want the ex PMR Pye 'Wessies' (probably already pulled onto 2m) I'm about to put in the skip Harry?

Indeed .. I might take one from here and see how well it works around the greenhose. I know my DECT phone works everso-well down the garden up to my 8' square steel garage doors ..

Probably not ..

My only *worry* is how well all that electronics will fair in such heat and humidity? Different if it was MIL spec ;-)

I was thinking further about that and thought of fitting a DECT phone on the wall in a tupperware box with the bottom of the box trapped against the wall. In the morning you remove the lid take out the handset and refit the lid over the base. Maybe some silica gel bags in there and dried in the oven now and again ..?

All the best ..

T i m

[Owain]

"Dave Plowman" wrote | > The old carbon microphones do go bad over time and are | > usualy the source of the crackles. | A few thumps on the palm of the hand often sorts them.

Alternatively there is usually someone offering the electret drop-in replacements (red plastic capsules) on Ebay.

Owain

[Harry Bloomfield]

It happens that T i m formulated :

I suggest it would make little if any real difference to the coverage area.

The signal will reflect and bounce around well enough I think.

Probably rather too old to be of any great interest to the rest of the community.... Send me an email with your details and the details of the equipment and I will ask around.

Generally the higher and more central the base, the better the coverage, but I suppose you already knew that.

I looked into doing that some time ago to cover a 3/4 mile long U shaped factory site. It was possible, but the repeaters were horifically expensive. About a couple hundred pounds each I seem to remember.

I rather assumed there might be a separate office that the base could be installed in.

That would work.

Another idea might be to include the power supply transformer in the same sealed box. These generate a small amount of surplus heat, probably enough to keep it dry inside especially if a small amount of ventillation is allowed in the lower face of the box.

[Lobster]

Sounds like the phone wiring is already in place though, in which case it's got to be worthwhile using it...

I'd look at Ebay: from what you say you need more than one phone and there are often listings of job lots of cheap phones on there. Also, I recently bought a brand-new Binatone wall-mounted speakerphone from Ebay; I think it cost 2 or 3 quid?! A speakerphone would probably be handy for a greenhouse, for when the user is up to his eyes in mud etc

David