This type of pump was supplied by Andrew Antenna Co. It was used to pump dry air into the waveguides of microwave antennas as used by the telephone company, satellite communications stations, etc.
Cool dry air in the waveguide ensures the best possible signal propagation characteristics especially in the higher frequencies (X, K band, etc) where the microwave signal is partially attenuated by airborne water vapor.
They don't use these anymore - in modern microwave systems the waveguide is purged with nitrogen from a tank. I'd really like to have a pump like this !
===================================================== Mark Petry 206.618.9642 Beautiful Bainbridge Island, WA mpetry@bainbridgeisland.net
===================================================== "Nothing can match the simple pleasure of a bicycle ride"
John F. Kennedy (Sr.) =====================================================
From: "David Bilenkey" <dbilenkey@sympatico.ca> To: "Classicrendezvous" <classicrendezvous@bikelist.org> Subject: [CR]FW: Pump parts?
Has anyone on the list heard of this before? If you can offer any info or advice on what to do I'll pass responses on to my friend.
Thanks in advance,
David Bilenkey Ottawa, Ontario, Canada
-----Original Message----- From: Simpson, Bob Sent: August 5, 2003 11:07 AM To: David Bilenkey (E-mail) Subject: Pump parts
Hi David,
A friend at work has what looks like an antique bicycle pump, which has a cylinder around the outside with desiccating material so that the air pumped is dry. It was actually discarded from the NRC, so it might not have been originally designed for bikes. It's called an Andrews 876-A pump and has a barrel 34 mm in diameter. Have you ever heard of such a pump and do you have any sources for replacement pump parts? The leather washer/plunger has torn.
Bob Simpson