Home
Sound
Car Audio
Cabling
Amplifiers
Valves
Speakers
CD Players
Recording
Surround Sound
Radio Tuners
Vinyl Records
Guitars
Drums
Microphones
Mixing
Computers
Synthesisers
Tape Recorders
Headphones
Transformers
Other

strange DAB phenomenon



I recently got a Pure Evoke 1XT, and it works very well, though I
think I'm on the borderline of a good reception area, as I have to
position the radio carefully to get good reception.

But I've noticed something strange when I switch it on in the morning.
For the first 3-5 minutes, I get perfect reception, then it gradually
gets worse over a minute or so, until the output is totally
unintelligible, and the 'signal quality' read-out is way down to 30 or
so (from the 100 it was when I switched on). This lasts for about 5
minutes, then reception climbs back to 100, and I have no more
problems for the rest of the day.
I had a Pure Evoke-1 which started doing something similar after about a
year although it did not get better after a while as yours does. Signals
would degenerate into total burbling and stay like that - signal strength
at full-scale. Sent it back to Pure who replaced it and said it had been
'crystal drift' so there must have been an off-frequency crystal oscillator
causing decoding errors. But I can't see this being the cause of your own
problem as yours recovers after a further 5 minutes you say.
Perhaps a crystal is just slightly off, and varies as things warm up.
My Blaupunkt Woodstock dab54 has always done the same thing: In cold
temperatures it start, but after maybe 15 seconds it starts fading
deeply (the s-meter going from full to zero even though we are next to
the transmitter). This lasts for about 3 minutes, after which operation
"cold temperatures" ? :-)
On a chilly day like today it was 10C, which causes the Woodstock to
fade briefly after turn-on. Anything colder will cause more severe
fading. Below freezing point you don't get to listen to dab on a short
trip. That's why I use fm for the first 5 Km.

1999 we have -49.0°C in north Sweden (Lappland).
1966 we have -52.6°C in north Sweden (Lappland).
It's all relative.

When my Auntie and Uncle came back from Cyprus, they said that in winter
time if the temperature went below 80 (that's Fahrenheit, it would be
about 25+ in Celsius) the locals would be sitting around their log
fires, thinking it was cold.

Here in the UK, 80 degrees is considered a bit of a heatwave.

Richard E.

is normal.


Richard E.


(The replacement Evoke is still OK at the moment!).


Does anyone here know what's happening? It can't be the radio 'warming
up', or else why would reception be perfect for the first few minutes?
Are you having a shower or using electrical equipment that might
interfere with the radio. Shower certainly affects mine. Modem does
too.