Jimmy wrote:
"W5DXP" wrote: I control the switches from my shack. They are mounted on a piece of plexiglas sitting vertical in a window. It takes less time to throw the switches than to tune an antenna tuner. Really, some how or other I got the impression you had to go outside to change bands. The window-line loops are outside but the switches are inside. I've got a chart on the wall that makes changing bands a snap from the operating position. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =----- |
In a time long, long ago, there were no commercial antenna tuners that
I can recall. The first commercial tuner I remember was the Johnson Viking. Everyone I knew made their own. You just went to the surplus store, and got a coil and capacitor that looked about right, and tried it. No one owned any equipment to measure them anyway. We never used relays. Maybe a switch, or just change the coil. The ARRL handbook and Antenna Handbooks still have diagrams for antenna tuners. Also the Hints and Kinks manuals, among many others. Dick - W6CCD On 4 Aug 2003 12:51:51 -0700, (Art Unwin KB9MZ) wrote: Mark, What sort of range of impedance matching would this provide? How would you switch bands and what voltage/capacitor range would be required? I suspect you would have to have several relays to pick up various points on the oatmeal inductor as well as a rotation method for the capacitor Seems like you have something specific in mind that you would put in a box for safety reasons. Are the specifics shown somewhere for people to copy? Art |
Dick, A REAL LONG time ago when I needed my first tuner I bought a
military surplus ARC-5 transmitter for $5 USD and removed the roller inductor and final plate tuning capacitor. [Actually, I bought 3 ARC-5s: one for 80, one for 40 both converted to XTAL control, and one for the tuner and spare 1625s. Nice NOVICE CW rigs.] Made a real nice L-tuner at 125 watts continuous duty!! Hmmm .... where are those old ARC-5s when someone needs them?? Deacon Dave, W1MCE Dick wrote: In a time long, long ago, there were no commercial antenna tuners that I can recall. The first commercial tuner I remember was the Johnson Viking. Everyone I knew made their own. You just went to the surplus store, and got a coil and capacitor that looked about right, and tried it. No one owned any equipment to measure them anyway. We never used relays. Maybe a switch, or just change the coil. The ARRL handbook and Antenna Handbooks still have diagrams for antenna tuners. Also the Hints and Kinks manuals, among many others. Dick - W6CCD On 4 Aug 2003 12:51:51 -0700, (Art Unwin KB9MZ) wrote: Mark, What sort of range of impedance matching would this provide? How would you switch bands and what voltage/capacitor range would be required? I suspect you would have to have several relays to pick up various points on the oatmeal inductor as well as a rotation method for the capacitor Seems like you have something specific in mind that you would put in a box for safety reasons. Are the specifics shown somewhere for people to copy? Art |
Did the same thing!! Even used the chasis! Sawed it off, moved the front
cover/ cap, and rotary inductor into the area of the osc/ magic eye tuneing tube area-- makes nice package, and considering these tuned from around 160 meters thru 20 (or thereabouts) in different versions, and loaded a aprox 20 foot piece of wire--- make very versatile tuners . also wonder where all of the bazillions of these dissapeared to! Jim Dave wrote: Dick, A REAL LONG time ago when I needed my first tuner I bought a military surplus ARC-5 transmitter for $5 USD and removed the roller inductor and final plate tuning capacitor. [Actually, I bought 3 ARC-5s: one for 80, one for 40 both converted to XTAL control, and one for the tuner and spare 1625s. Nice NOVICE CW rigs.] Made a real nice L-tuner at 125 watts continuous duty!! Hmmm .... where are those old ARC-5s when someone needs them?? Deacon Dave, W1MCE Dick wrote: In a time long, long ago, there were no commercial antenna tuners that I can recall. The first commercial tuner I remember was the Johnson Viking. Everyone I knew made their own. You just went to the surplus store, and got a coil and capacitor that looked about right, and tried it. No one owned any equipment to measure them anyway. We never used relays. Maybe a switch, or just change the coil. The ARRL handbook and Antenna Handbooks still have diagrams for antenna tuners. Also the Hints and Kinks manuals, among many others. Dick - W6CCD On 4 Aug 2003 12:51:51 -0700, (Art Unwin KB9MZ) wrote: Mark, What sort of range of impedance matching would this provide? How would you switch bands and what voltage/capacitor range would be required? I suspect you would have to have several relays to pick up various points on the oatmeal inductor as well as a rotation method for the capacitor Seems like you have something specific in mind that you would put in a box for safety reasons. Are the specifics shown somewhere for people to copy? Art |
On Tue, 5 Aug 2003 16:15:32 -0700, wrote:
Well, depends on HOW CLOSE to my flesh I held it! (according to the inverse -square law, temperature decreases at a rate of 1/4 , for every 1/2 of an increment it is removed from you)! Jim NN7K Richard wrote: This 0.1dB in the wrong hands is clearly an example of extravagant dismissal or myopic attention. And speaking of hands, how long would you consider it trivial if you had to hold onto the sucker for 20 seconds? 73's Richard Clark, KB7QHC Hi Jim, How close is anything to your flesh when you are holding it? Are you still holding it, if it were 2 times further away? 73's Richard Clark, KB7QHC |
Jim, NN7K wrote:
"also wonder where all those bazillions of these disappeared to!" I think all the offshore counterfeiters of ARC-5 and 274-N equipment switched to modern equipment production when demand dwindled for surplus radios. Too bad! Best regards, Richard Harrison, KB5WZI |
Well, Richard, tho in jest, serves purpose, that even with 30 watts lost on
surface of a balun , (or any other surface, for thatr matter), that by doubleing the size of the SURFACE, that it would take something like 4 TIMES as much heat to destroy it. For the same reason that a transistor, in the size of a micron will vaporize with a slight static discharge , doesn't necessarily mean that a POWER transistor will even feel a hickup, if it takes you 30 minutes with a 100 watt soldering iron trying to get solder on the leads! For the same reason , have 50 ohm coaxial resistor that fits in a reducer for rg-174, to a SO-239, that would probably crack, with the heat, and meantime also have a resistor, 1/3 the size, but made to mount on a heat sink, that will dissipate 100 watts all day! (also made as a 50 ohm load-- same devices, but different uses-- Jim Hi Jim, How close is anything to your flesh when you are holding it? Are you still holding it, if it were 2 times further away? 73's Richard Clark, KB7QHC |
On Wed, 6 Aug 2003 15:48:01 -0700, wrote:
Well, Richard, tho in jest, serves purpose, that even with 30 watts lost on surface of a balun , (or any other surface, for thatr matter), that by doubleing the size of the SURFACE, that it would take something like 4 TIMES as much heat to destroy it. Hi Jim, No, this is incorrect. When discussing power dissipation, it follows a linear relationship to surface area - not square law (you are mixing radius and surface area arguments). Even letting this pass, power dissipation does not even conform to doubling with doubling of surface area. This departure from expectation arises in the increased distance the heat has to travel to find the surface. This is usually found in having too many fins in an effort to maximize that same surface area (and leads to an increase in Thermal Resistance). Further, more fins also diminish heat transfer through convection (again increasing Thermal Resistance). 4 or 5 fins is usually optimal. 73's Richard Clark, KB7QHC |
I read some of the return messages and I noticed that the message initially
openned by saying that many hams still use a long wire and tuner. He comments to say that the long wire is cheap but the tuner is not. That kinda hit a cord with me because of my antenna experiences. I have been an amateur since 1964, thats not a brag just a comment. Besides using a random wire antenna, I have tried multi-band dipoles, quads, beams, folded dipoles and others. However, I still keep coming back to my old reliable random wire, about 60ish feet and an L network (the coil connecting to the transmitter and the capacitor connecting between the ground and the common connection of the coil and antenna). Though a very simple circuit, it works very well. Recently I put up a 30ish foot random wire and found that it didn't work on 80, using the L network. After some thought, I broke the random wire and inserted a coil. I now gives me a good swr on 80 meters. I just wanted to defend cheap, but highly functional, antenna couplers and cheap but useful random wires. Larry ve3fxq Sorry if I have come accross a little rough sounding. "Art Unwin KB9MZ" wrote in message m... Seems like a lot of hams with limited resources are still compelled to operate on many bands with just a long wire and a tuner. The wire is inexpensive but the tuners are not. Thus my present project. I was given a Palomar enginnering balun with 5 female connenection which by selection can match a antenna in steps from 5 ohms to over 450 ohms in a series of steps. I am presently rigging it up so that all steps can be switched thru remotely by a single motor. The switching arrangement is the main challenge since inexpensive means simple. Now I have not measured losses of the balun before hand because the switching challenge is what is driving me. Anybody have any thoughts about what I should expect from this balun other than knowing that it is not a tuner as is generally known since it does not have the ability to obtain the priceless 1:1 condition that so many desire? Regards Art |
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