Topic: Low temp issues.

[Rickard]

I tested my old (almost) faithful 981 in cold weather today, ice-scanning in - 32 C (around -25 F), and thought it worked fine until I inspected the recordings with a computer. The dreadful gaps from last summer were there again! I tested with a fast (45 MB/s) card and a slow (15 MB/s) card and there were gaps (= memory loss) with both cards. The gaps ocurred at longer intervals (about once a second) with the fast card and about three times per second with the slow card. The fast card shows memory loss in summer too, but the slow card shows almost no signs of memory loss in the summer. There is no lowest temp recommendation in the specs for the unit so I wonder if I might have asked too much from my 981? Is there any reason to expect an effect of temp on memory storage performance?
Rickard

[sonar2000]

Couple of things, and I am with you as I cant find the temperature range for the unit either,
The unit might be cold and the cold is affecting the card slot. or could some small moisture have gotten in the slot and the 25 degrees be freezing. maybe coming from a warm humidified room and going into the cold caused some condensation...

Are you fishing in a cabin/tent or out in the open? It does sound like a temp issue.

I will do some more checking for the low/high temp range.

Chuck

[Rickard]

I put in the first card indoors, before leaving for the expedition, and when I changed cards they had the same temp as the unit had so there should not have been any condensation phenomena. I scanned in the open. I know these issues appear also at -25 C, but the slow card performs well at -15 C ( 5 F) (The fast card causes data loss at all temps). These temps do not tempt for excursions or fishing trips, but I was curious to see where the limit is.
 
I think the overall low temp performance of the unit is quite impressive. The display doesn't freeze (as the external Garmin GPS disply does), the buttons feel like in warm weather and the unit seems to process all menu settings as usual. The transducer cable gets very stiff though.
 
Rickard

[sonar2000]

Good deal, for those who use in the cooler weather this is good news...
Still dont know why the unit hesitates though..
Chuck