On offer is a used two gang 90pF + 90pF air dielectric variable capacitor of compact size which was manufactured by Jackson Brothers in the UK. This example was used by the RAF /Air Ministry and has the indistinct AM Reference No. stencilled on the front plate.

It measures about 2.75 inches [including rotor shaft] x 1.75 inches wide x 1.35 inches from the base to allow for the rotor swing and is mounted by screws into threaded bushes on both the front and back plates. The rotor is mounted with a ball race at each end, and has a 0.25 inch diameter shaft which is about 0.30 inches long.

I have listed it as 90pF + 90pF, but the actual values are 9.7pf to 91.9pF on one gang and 9.3pF to 91.2pF on the other - see photographs 9, 10, 11 and 12, measured on a Peak LCR40 component analyser,  [for info], and is in working order.

This has the partial Air Ministry Reference No. on the front plate [shown in photograph 7] and these were used extensively by the RAF and the Air Ministry on wireless and radar equipment during the 1940s and 1950s.

Description and condition can better be judged from the photographs, which are of the actual capacitor on offer for sale.

This has been priced to sell, without reserve.

Please see the other items which I have on offer for sale.

BEFORE BIDDING, PLEASE READ ALL OF THE TERMS AND CONDITIONS BELOW.

1. PLEASE LOOK CLOSELY AT ALL OF THE PICTURES; THIS IS THE EXACT ITEM ON OFFER AND FORMS THE DESCRIPTION WHICH MAY TELL YOU SOMETHING THAT I HAVE NOT MENTIONED.

2. BUYERS PLEASE NOTE THAT PURCHASES ARE PACKED AND SENT IN BOXES, NOT PADDED BAGS, IN AN ATTEMPT TO PREVENT DAMAGE IN TRANSIT.

3. I WILL TRY TO COMBINE POSTAGE ON MULTIPLE PURCHASES WHERE POSSIBLE, PROVIDING THAT THE COMBINED WEIGHT DOES NOT EXCEED 2KG. IF IT DOES I WILL TRY AND PACK AND POST PARCELS WITH THE MOST BENEFICIAL COMBINATIONS.

4. OVERSEAS BUYERS PLEASE NOTE THAT I ONLY SEND PURCHASES THROUGH eBay Global Shipping Program. CHECK eBay CHARGES BEFORE BUYING AND NOTE THAT I CANNOT COMBINE POSTAGE COSTS WITH OTHER GOODS PURCHASED. EACH PURCHASE WILL BE PROPERLY PACKAGED AND THE POSTAGE STATED WILL BE CHARGED.

5. THE GLOBAL SHIPPING PROGRAMME ALREADY PROVIDES THE BUYER WITH AN INVOICE FOR ALL APPLICABLE ITEMS, POSTAGE AND IMPORT CHARGES. Unfortunately, eBay will NOT allow me to edit these charges, or even to offer a P&P discount. The buyer will directly pay the purchase price of the item to me, plus any domestic postage cost as specified in the listing.

6. If you are unhappy with any of my terms and conditions please feel free to buy from another seller.

DOL260523.