[OT] Best orientation of thermometer sender ?

The router's wall-wort PSU might also be putting out interference.

No, it's near Wentbridge. There's no obvious suspect.

Bill

Realistically you can only do this empirically, move the device a few inches and see if there is an improvement. I realise this is difficult if it works OK most of the time.

What I don't see mentioned in the advice so far, is that moving the position and/or orientation of the receiver is just as valid as the thermostat, and as it is likely to be out of sight in the boiler cupboard you can probably be more imaginative with that unit, especially if there is some slack in the cabling.

Bare in mind that at 433.92MHz a movement of a few inches can make the difference between an unusable signal and a good one.

Keep up at the back I covered this in previous lecture.

The rubber ducks have rather unimaginative name of "normal-mode helical"

That's what I thought at first glance, but since then we've been told it works on 433MHz, so it is probably a plain plastic former. On reflection the coil is wrong too (too few turns and spaced out inappropriately for a ferrite aerial).

In addition to Graham's valid points, things like metal objects, even mirrors (which have a metal film on the rear) can cause reflections, 'dead spots' etc. We have an FM/DAB clock radio which, in FM mode, doesn't like the mirror doors on our wardrobes in a certain position. It is fine in DAB mode.

Just to be clear, the sensor is not indoors. It's actually on top of a washing line pole in the garden and in line of sight (through a window) of the indoor display unit. So I can't easily move it a few inches sideways.

It's placed at the top of a pole in order to get a reasonable air temperature reading without influence from garden vegetation or from cold air on the ground. Well, that's my theory!

Perhaps Bill has his mind on the somewhat surprising story he told recently.

Did you really find it so surprising? If so I'm guessing you don't know much about little boys, particularly how disgusting they can be!

Bill

True, but wouldn't the polar diagram be similar whether or not there is anything in the former?

Roughly, yes.

However, there are other pointers to it not being ferrite- in particular the frequency these beasts work on.

I can't look inside to check because the unit in the photo has been reassembled and is now back in the garden.

There are two many turns for it to be ferrite, given the frequency.

It is, as previously stated, a crude 'rubber duck(y)' antenna rather than a 'loopstick' coil as typically found in a LW/MW radio.

At 433MHhz you don't need ferrite for an antenna that sort of size. a quarter wave whip is only 6", so a couple of inches of helix will get you to resonance