I had the same problem a few years back and was thinking about a hipmount type kit. Then again a extention cord may or may not change the performance and did i really want the rather huge hipmount unit on my side.
I decided to rearrange the whole machine and make it better balanced instead, after all whites make juat as heavy detectors but all weight are balanced out so very very nicely that its a breece to detect with them. A whites, if you rest it on your finger right under the grip it actually balance in the position you detect with it in.
So what i did was i bought a complete whites stem and made a bracket to hold the housing and made a new battery pack at the rear end. my effort was to get the balance point as far back as possible and i made it. My explorer now balances out like a whites and it isnt any heavier.
I changed the location of the headphone connector to the back of the housing.
Ill attach a pic of the finished detector.
terry