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Wed, 26 Dec 2007
SRV-1 antenna issue
An observant SRV-1 customer noticed some signal strength issues with his robot at longer range, and then asked why neither the 3db antenna nor the SMA bulkhead connector on the SRV-1 seemed to have a center pin. And he was right - there is no center pin, and therefore no connection between the antenna cable and the antenna.
One would expect that we might have noticed this in the 1.5 months the new SRV-1 has been shipping, but we didn't - we configure and test the WLAN radio modules and robots without antennas, as the radio module has pretty good range without one. We only add the antenna to the shipping box as a final step before taping things shut.
There is an easy fix. The pin diameter is approximately the same as 18 gauge wire (approx 0.9mm or 0.035"), and a 0.250" - 0.300" (6.5mm - 7.5mm) length of 18 gauge solid copper wire seems to work nicely. At the hardware store, they refer to this 18 gauge wire as "Bell wire" or "telephone wire".
The only trick is to straighten the wire before insertion and make certain the wire end isn't flattened where it has been cut, but this can be corrected with pliers.
We contacted the antenna manufacturer and learned that both the SMA bulkhead connector and the antenna can be ordered with the center pin, but we had neither, and nobody flagged this before. In the future, we will order the SMA connectors with pins, and until the new cables arrive, we will add a pin to the antenna for new shipments.
By all reports, this fix is working well. We are somewhat embarrassed to have missed this, but are at least glad that our users are paying attention.
Posted Wed, 26 Dec 2007 20:29 | HTML Link | see additional stories ...