Thanks to George WB5VZL for forwarding this summary to the KA9FOX web site! ------------- From: Jay Kesterson Subject: Summary: Coax switches & Wattmeters (long) To: vhf@w6yx.stanford.edu Date: Fri, 28 Jun 1996 09:15:09 -0700 (MDT) Here is a summary of the data I received from my request for info on V/UHF wattmeters and multi position coax switches. 73, Jay K0GU DN70mq jayk@fc.hp.com ----------------------------------------------------------------------------- --As a suggestion, there are 3 and 4 position versions of the transco "y" relay out there, I see the things at flea markets often..... .......You may want to look at the TOH-TSU relays. A bit expensive but they spec at least 60 dB isol. and --I think-- are available in a few different configurations. Harry WA1VVH ----------------------------------------------------------------------------- I like (very much) the Alpha-Delta 4N switches. They're not cheap, but I think they're the best you'll find, short of the six-position Bird model 30-something, I think), which uses a plunger-type mechanism. Check out the AD ads in QST--the switches were featured there within the past two months. Bird makes a 2.5-kW element for the 43. It's typically a special-order thing that goes for around $70. Check with Texas Towers or your favorite Bird distributor for more info. Of course, you can also check with Bird. They have good customer service people. Rus Healy, NJ2L ----------------------------------------------------------------------------- Call Bird. Their catalog says 2500C (for 144) takes 2500W only on peak, and only 1000W key-down. But the engineer on the phone says they have upgraded the specs. 2500W okay key-down now. Mark, K5AM ----------------------------------------------------------------------------- Check with Jeff, K3DUA, at G & G Electronics in Gaithersburg, MD. 301-258-7373. He should have watt meters, elements, and maybe the switches you need. Tell him I sent you. Thom, W8HBN ----------------------------------------------------------------------------- Jay, I like my Mirage MP2 50-200Mhz meter. 50, 500 and 1500 watt scales. Mimmicks my Bird up to a KW and has true peak reading as well as average. Also does manually calibrated SWR. I only have one and use it on 6 or 2 so intend to buy another. I have had this one about a year. Price around 200 bux. Mike KS0F ----------------------------------------------------------------------------- I have some switches, relays and a struthers meter that will measure your stuff. Send me your postal address and I'll mail you a list. pete kn6bi pgerba@crl.com ----------------------------------------------------------------------------- If by coax switch you mean a remote switch that connects one feedline to several different antennas, you can readily obtain these in 28 volt models that will handle the legal limit on 2 and I think the legal limit on 432. These are called "globes" because they look like a globe in shape and they appear at flea markets and are sold by a number of dealers. They are all surplus (you couldn't afford a new one). They come in 2, 3 ,4 and if you get real lucky 6 port versions and are made by Transco, Thompson, and other manufacturers. My commercial source is Joel Knablock at the RF Connection here in Gaithersburg 1-800-783-2666. He should have the specs as well (these are hard to come by). As for wattmeters, you CAN buy a 2500 watt Bird slug at VHF ...... If you can survive with somewhat less accuracy, the DAIWA NS660PA works fine on 2 meters at up to 3 kw (so it sez). For 432 you have to sell the family jewels and get a Bird. The coaxial dynamics is supposed to be good but I am not sure it can measure 1500 watts without some kind of mod or add-on. Someone else will have to tell you about that (consult your banker as well). Gene W3ZZ ----------------------------------------------------------------------------- Transco makes multiposition switches. I have a 4way switch p/n 14100 (30 years old). It was used in military aircraft. Switch is spec'd at 500watts continuous. n7wls (miles) ----------------------------------------------------------------------------- Bird does make 2.5KW slugs for 100-250Mhz (part number 2500C) its a special order item and may take a few weeks. Contact your normal Bird dealer and they should be able to get it for you. I have an 8938 on 432 and use the 2.5KW slug for 400-1000Mhz and have been very happy with it. One thing to remember is that the model 43 wattmeter is only rated for 1KW continuous. The slug may read 2500W Peak and 1000W Cont (mine does;-). Don't worry the scale will be correct just don't key down for more than a minute or two with the meter in line!! N connectors are recommended although the newer DIN's are better for continuous high power (more surface area on the center pin). I have no real experience with Coaxial Dynamics meters outside of high power broadcasting applications. They make good line sections, but so does Bird. de WB7TDI