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Old July 25th 19, 08:07 AM posted to rec.aviation.soaring
John Foster
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Posts: 354
Default Cambridge CPT 505 Variometer

On Saturday, July 20, 2019 at 7:22:32 AM UTC-6, wrote:
On Thursday, July 18, 2019 at 8:32:04 PM UTC-6, Nick Kennedy wrote:
John
Buy yourself a early Christmas present and buy a LXNav S3 or S7.
Craggy will send you one tomorrow.


John. I have a v7/S7 in like New condition if you are interested. Fair price. Email me if you are interested.


My dad, who is really smart with electronics, thought that it may be a capacitor problem, as the instrument has not been used in over 20yrs probably. He decided to try to "heal" the capacitors by applying a lower voltage to the instrument and gradually increasing it over time. We started at about 8 or 9 volts (don't remember exactly) and gradually increased the voltage in increments of 1.5 V over the course of the next 2-3 days, maxing out at 17.5 V. The instrument is rated to 18V at 300mA. He made sure the power supply was set to not deliver more than 250mA just in case. After the treatment, the vario will still have a full negative and positive deflection when powered up, for about a minute or two, and then settles down around the zero mark. I haven't gotten to test it out in flight yet, but this seems promising.