A
Anonymous
Guest
To all those interested in noise,
The 5534 is definitely the best of the three for noise performance in a PI. Measured peak to peak noise at the output of the analog integrator in a Goldquest is 3.5mV, 10mV and 6mV respectively. The results are similar with a 10in search coil connected and aligned for minimum noise pickup, or with the transmitter disabled, no coil connected, and input to the amplifier circuit shorted. The readings were taken on a storage 'scope and allowed to build up over a few seconds on long persistance. It is the occasional low frequency bounce that is the culprit. You can definitely hear the difference on the headphones, with the 5534 being much smoother. I was surprised that the 8031 was worse than the 8055, as the data sheet indicates it should be the other way round. Still, I only tried one sample of each.
Eric.
The 5534 is definitely the best of the three for noise performance in a PI. Measured peak to peak noise at the output of the analog integrator in a Goldquest is 3.5mV, 10mV and 6mV respectively. The results are similar with a 10in search coil connected and aligned for minimum noise pickup, or with the transmitter disabled, no coil connected, and input to the amplifier circuit shorted. The readings were taken on a storage 'scope and allowed to build up over a few seconds on long persistance. It is the occasional low frequency bounce that is the culprit. You can definitely hear the difference on the headphones, with the 5534 being much smoother. I was surprised that the 8031 was worse than the 8055, as the data sheet indicates it should be the other way round. Still, I only tried one sample of each.
Eric.