|
Reg: Here is the SWR bridge I attempted to describe...
This is a SWR bridge I built using leds and a homemade "directional
coupler." ALL critiques on it, and ideas for improvements are welcomed!!! Please excuse my rough drawing, I am NOT a draftsperson! Hopefully, the attachment of the .jpg was successful.... Warmest regards, John |
.... and, if I read the datasheet of the mpf-102 fet correctly...
I think it could replace the 100k and 1k by connecting the drain to the leds anodes and source to ground, taking the mpf-102's drain to ground with a 1k resistor--should function to limit current through leds to 10Ma.... Regards, John "John Smith" wrote in message ... | Hopefully, the attachment goes this time!!! | | Regards, | John | | "John Smith" wrote in message | ... || This is a SWR bridge I built using leds and a homemade "directional || coupler." || || ALL critiques on it, and ideas for improvements are welcomed!!! || || Please excuse my rough drawing, I am NOT a draftsperson! || || Hopefully, the attachment of the .jpg was successful.... || || Warmest regards, || John || || | | | |
John Smith wrote:
Hopefully, the attachment of the .jpg was successful.... The usenet gods will not allow .jpg files since this is specified as a text only newsgroup. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Oh great!!!
Can I just rename it? What is a workaround? Or, do I have to get a free host and setup a webpage? Regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | Hopefully, the attachment of the .jpg was successful.... | | The usenet gods will not allow .jpg files since this is | specified as a text only newsgroup. | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
I've a horrible feeling this (not your SWR bridge) is not going to
work. Where is your .jpg ? I can't find it. Does Cecil's comment mean that it is impossible to attach it to a newsgroup message. Or does it mean only that the powers that be won't like it. There's another problem. If you attach anything to an e-mail there's a fault in my computer and I shall be unable to open it. When it comes to operating a computer I am just a novice. By the way, have you actually got your bridge to work in some fashion or other? If it's still only on paper the likelihood of me being able to make any sensible comments is pretty poor. But I'll try. There is a program on my website named SWRMETER which you may care to amuse yourself with. ---- Reg. |
John Smith wrote:
Oh great!!! Can I just rename it? What is a workaround? Or, do I have to get a free host and setup a webpage? Web pages for hams are available on qsl.net. Or send it to me and I will post it for you on http://www.qsl.net/w5dxp/filename.jpg -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
OK, one... more.... time!!! there is no time yanno!
Please someone, see if you can view the page he http://blake.prohosting.com/mailguy2/JS-swr.jpg Warmest regards, John "John Smith" wrote in message ... | This is a SWR bridge I built using leds and a homemade "directional | coupler." | | ALL critiques on it, and ideas for improvements are welcomed!!! | | Please excuse my rough drawing, I am NOT a draftsperson! | | Hopefully, the attachment of the .jpg was successful.... | | Warmest regards, | John | | |
Reg:
Yanno, you remind me of my mother, she had about the same amount of faith in me!!! grin Here ya go Reggers!!!! http://blake.prohosting.com/mailguy2/JS-swr.jpg Warmest regards, John "Reg Edwards" wrote in message ... | I've a horrible feeling this (not your SWR bridge) is not going to | work. | | Where is your .jpg ? I can't find it. | | Does Cecil's comment mean that it is impossible to attach it to a | newsgroup message. Or does it mean only that the powers that be won't | like it. | | There's another problem. If you attach anything to an e-mail there's a | fault in my computer and I shall be unable to open it. When it comes | to operating a computer I am just a novice. | | By the way, have you actually got your bridge to work in some fashion | or other? | | If it's still only on paper the likelihood of me being able to make | any sensible comments is pretty poor. But I'll try. | | There is a program on my website named SWRMETER which you may care to | amuse yourself with. | ---- | Reg. | | |
Think I managed it Cecil... but thank you very much for offering to help--it
IS appreciated deeply here... Try this link: http://blake.prohosting.com/mailguy2/JS-swr.jpg Warmest regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | Oh great!!! | Can I just rename it? | What is a workaround? Or, do I have to get a free host and setup a webpage? | | Web pages for hams are available on qsl.net. Or send it to me and | I will post it for you on http://www.qsl.net/w5dxp/filename.jpg | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
John Smith wrote:
OK, one... more.... time!!! there is no time yanno! Please someone, see if you can view the page he http://blake.prohosting.com/mailguy2/JS-swr.jpg You have a number of problems. Where did you get that design? In order to separate the forward power from the reflected power, you need to use phasor addition/subtraction of voltage and current. You only have current sampled. Where is your voltage sample? Where is your phasor addition/subtraction? -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
On Tue, 3 May 2005 17:18:33 -0700, "John Smith"
wrote: OK, one... more.... time!!! there is no time yanno! Please someone, see if you can view the page he http://blake.prohosting.com/mailguy2/JS-swr.jpg Yes, John, it's there. No problem. Bob, W9DMK, Dahlgren, VA Replace "nobody" with my callsign for e-mail http://www.qsl.net/w9dmk http://zaffora/f2o.org/W9DMK/W9dmk.html |
Well, can't remember where I seen that "directional coupler", but will be
willing to give the designer credit if he makes himself know... The led indicating circuit is my design... It seems to work, all I have is another SWR with analog meter I constructed myself to compare it with, soon as I locate someone with a commercial meter--I will compare both of mine to it... Only real apparent problem is the REF led changes brightness slowly (and here it is hard to "judge" SWR by brilliance), until right at, or near, match, when it will plunge to darkness rather quickly... Well, show me what is wrong and suggest an alternative circuit or mods to set it proper (or explain in text, I will see how good I am at word problems here)--I am all EARS Cecil... smile Regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | OK, one... more.... time!!! there is no time yanno! | Please someone, see if you can view the page he | http://blake.prohosting.com/mailguy2/JS-swr.jpg | | You have a number of problems. Where did you get that design? | In order to separate the forward power from the reflected | power, you need to use phasor addition/subtraction of voltage | and current. You only have current sampled. Where is your | voltage sample? Where is your phasor addition/subtraction? | -- | 73, Cecil http://www.qsl.net/w5dxp | | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups | ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
On Tue, 3 May 2005 17:18:33 -0700, "John Smith"
wrote: Please someone, see if you can view the page he http://blake.prohosting.com/mailguy2/JS-swr.jpg Hi Brett, A most unusual indicator if ever I've seen one (and I've seen many). What you have (if you can generate enough voltage - it will take about 35-40W of transmit power) is an emergency flasher weakly lighting the alternate LEDs at an HF rate. This is with Red LEDs, as I offered in another posting, if you tried with Blue LEDs, you would need more like 170W to weakly light them. The 100K is literally useless (as are the 1N914s), and the 1K is a severe handicap. Once you get past those limitations you will have a brighter flasher at no big hit to the overall efficiency - if a flasher is what you want. Mad Man Muntz with his dikes would have a glorious time trimming back the excess here. It might sell well to the CB crowd that wants 27 MHz strobing brake lights. Could even perform better for night time DX than some rear mounted bumper whips. Perhaps a better use of their linears - as legal power won't light this circuit. 73's Richard Clark, KB7QHC |
On Tue, 03 May 2005 22:12:31 -0700, Richard Clark
wrote: an emergency flasher weakly lighting the alternate LEDs at an HF rate. On review of the circuit (having neglected the capacitors) it looks more like a lower rate in a somewhat haphazard logic race of a relaxation oscillator whose RC (1K-101K times 0.01µF) still makes this wobbulate at higher than visible rate (or lower than perceptible brightness, take your pick). 73's Richard Clark, KB7QHC |
grin
Ahhhh, Richard, your armour and weapons rattle as you come down the hall... Well, it doesn't flash, and it does seem to work... albeit in a bit of a "sloppy" fashion (tuning is sloppy as to light changes in the REF led)... and you are correct, the 100k (and the 1k is there in series too) is barely enough to keep from burning out the leds and a kludge... If you HAD to make this circuit work, I am interested, and certainly I think you of an intellect capable--what changes would you make--keeping as much of the original circuit as possible? Warmest regards, John "Richard Clark" wrote in message ... | On Tue, 03 May 2005 22:12:31 -0700, Richard Clark | wrote: | | an emergency flasher weakly lighting the alternate LEDs at an HF rate. | | On review of the circuit (having neglected the capacitors) it looks | more like a lower rate in a somewhat haphazard logic race of a | relaxation oscillator whose RC (1K-101K times 0.01µF) still makes this | wobbulate at higher than visible rate (or lower than perceptible | brightness, take your pick). | | 73's | Richard Clark, KB7QHC |
On Tue, 3 May 2005 22:31:29 -0700, "John Smith"
wrote: Well, it doesn't flash, Hi Brett, How could you tell? Everything about this is far too fast for the eye to perceive. But we let that pass. and it does seem to work... albeit in a bit of a "sloppy" fashion (tuning is sloppy as to light changes in the REF led)... and you are correct, the 100k (and the 1k is there in series too) is barely enough to keep from burning out the leds and a kludge... Barely enough? The problem is it is far too much. You would have to pump 3KW (matched) through this SWR meter to run the forward LED at rated current. The eye is a miserable detector of absolutes, and what you perceive as bright with whatever current is eking its way through the circuit, is a sad comparison to what the LED could support. The proper comparison is done by what is called optical pyrometry, but then that is the wrong kind of balance for this application. If you HAD to make this circuit work, I am interested, and certainly I think you of an intellect capable--what changes would you make--keeping as much of the original circuit as possible? Research the "Bruene SWR meter" to find out where you went wrong in the circuit topology. If you are going to substitute LEDs for meters, take heed that they are power indicators, not current indicators. This is some advantage in one sense, and a divergence from the standard presentation in another sense. Not keeping track of the sense can get your necktie wrapped around the axle. Mixing LED types like for Green forward power and Red for reverse power (or t'other way 'round) can really gum up the works when it comes to sizing other component values. A simple test of how confounding the eye can be is found in the question: "How bright can the Red be in proportion to the Green?" By the simple electronics, this is a slam dunk. By appearance from those same electronics, you are off by two orders of magnitude. By conversion efficiencies there are still major errors of appearance. Once you get all these balanced out, you still have to answer the question whose psychology will still perturb most users. Try writing the answer for a User's Manual (the ultimate test of functionality). 73's Richard Clark, KB7QHC |
John Smith wrote:
It seems to work, all I have is another SWR with analog meter I constructed myself to compare it with, soon as I locate someone with a commercial meter--I will compare both of mine to it... Only real apparent problem is the REF led changes brightness slowly (and here it is hard to "judge" SWR by brilliance), until right at, or near, match, when it will plunge to darkness rather quickly... You are not reading SWR. All you are reading is net current. Both LEDs have the same rectified net current through them. Well, show me what is wrong and suggest an alternative circuit or mods to set it proper (or explain in text, I will see how good I am at word problems here)--I am all EARS Cecil... smile Here's the last one I looked at: http://www.mfjenterprises.com/man/pdf/MFJ-974H.pdf You'll recognize the SWR circuitry at the input connector. Note the capacitive dividers. That's what your circuit is missing. Nowhere does your circuit sample the RF voltage. This type of SWR meter samples the RF voltage (using a capacitive divider) as one parameter. It samples the RF current (using the toroid) as the other parameter. The two parameters are added before rectification to obtain the forward power. The two parameters are subtracted before rectification to obtain the reflected power. The phasor addition and subtraction must be done before rectification. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Well, If there is a voltage, there is a current (albeit, at times very
small)--the opposite is also true, ohms law is standing proof... Why can't I measure the standing wave ratio as a ratio of power, as opposed to voltage or even current reflected... the three are tied together, isn't it impossible to separate any one from the other two (and, I mean in reality, NOT in theory)--even though at times one can appear as insignificant to an observer? I see the design I sketched as an SWR device, perhaps not VSWR, or ISWR--but, PSWR... What would favor choosing the voltage device over the current or power SWR devices? Or, am I imagining something? Warmest regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | It seems to work, all I have is another SWR with analog meter I constructed | myself to compare it with, soon as I locate someone with a commercial | meter--I will compare both of mine to it... Only real apparent problem is | the REF led changes brightness slowly (and here it is hard to "judge" SWR by | brilliance), until right at, or near, match, when it will plunge to darkness | rather quickly... | | You are not reading SWR. All you are reading is net current. | Both LEDs have the same rectified net current through them. | | Well, show me what is wrong and suggest an alternative circuit or mods to | set it proper (or explain in text, I will see how good I am at word problems | here)--I am all EARS Cecil... smile | | Here's the last one I looked at: | | http://www.mfjenterprises.com/man/pdf/MFJ-974H.pdf | | You'll recognize the SWR circuitry at the input connector. Note | the capacitive dividers. That's what your circuit is missing. | Nowhere does your circuit sample the RF voltage. | | This type of SWR meter samples the RF voltage (using a capacitive | divider) as one parameter. It samples the RF current (using the | toroid) as the other parameter. The two parameters are added before | rectification to obtain the forward power. The two parameters are | subtracted before rectification to obtain the reflected power. The | phasor addition and subtraction must be done before rectification. | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
On Wed, 4 May 2005 09:14:37 -0700, "John Smith"
wrote: I see the design I sketched as an SWR device, perhaps not VSWR, or ISWR--but, PSWR... Not even that. 73's Richard Clark, KB7QHC |
Well, I should have stated my goal with this "eccentric device."
I wish an indication of SWR which is cheap, uses fewest parts possible, and has the possibility of "automatic operation" and one can be placed on each and every antenna I am playing with (or anything else, maybe one on the bird fountain! grin)... I bought a box of these LEDS at a surplus dealer, 10,000 LEDS in the main box, with 10 sub-boxes, each containing 1,000. They are a yellow/orange color--unique color to most I have seen... They seem to handle 20 ma for days on end with no problem--they are VERY bright at 5 ma (at least as bright as a "standard issue LED" at 10-20 ma)... The info on the box is as such: SIEMENS COMPONENTS Made in Malaysia LOT NO. 72870422 PART NO. Q6270303638 PRODUCT ID. LY 5436-TO DVP NO. 2605-9491-01 D/C: 9716 PROD NO. 97700420 I have done nothing but use them, have not even taken time to drop a VOM on 'em and measured the voltage drop across one--they are my favorite for projects (well, I am cheap and have a FEW of 'em!!!).... My design criteria a 1) CHEAP! 2) Cheap! 3) Few parts... 4) At least marginally workable... Warmest regards, John "Richard Clark" wrote in message ... | On Tue, 3 May 2005 17:18:33 -0700, "John Smith" | wrote: | | Please someone, see if you can view the page he | http://blake.prohosting.com/mailguy2/JS-swr.jpg | | Hi Brett, | | A most unusual indicator if ever I've seen one (and I've seen many). | | What you have (if you can generate enough voltage - it will take about | 35-40W of transmit power) is an emergency flasher weakly lighting the | alternate LEDs at an HF rate. | | This is with Red LEDs, as I offered in another posting, if you tried | with Blue LEDs, you would need more like 170W to weakly light them. | | The 100K is literally useless (as are the 1N914s), and the 1K is a | severe handicap. Once you get past those limitations you will have a | brighter flasher at no big hit to the overall efficiency - if a | flasher is what you want. Mad Man Muntz with his dikes would have a | glorious time trimming back the excess here. | | It might sell well to the CB crowd that wants 27 MHz strobing brake | lights. Could even perform better for night time DX than some rear | mounted bumper whips. Perhaps a better use of their linears - as | legal power won't light this circuit. | | 73's | Richard Clark, KB7QHC |
John (Smith), all you have is a circuit which might light up a couple of light-emitting diodes from an RF source via a current transformer. What purpose is served by the 100K resistor is anybody's guess. But it has nothing to do with SWR. As Cecil implies, you should go right back to square one and think about it. Actually, you are in good company. Most people don't know how their SWR meter works or what it does. Most people and Tx manufacturers don't connect it in the correct place for it read SWR on the transmission line. Consequently it doesn't even indicate SWR and its name is a very misleading misnomer. All it indicates is the magnitude of the reflection coefficient of the load on the transmitter relative to the impedance the transmitter is designed to see. And it only does THAT provided the meter has itself been designed to cater for the same impedance. It is fortunate there exists a standard impedance of 50 ohms. But don't allow me to put you off. Just obtain a circuit diagram of a so-called SWR meter (an HF version) from a handbook and, with little more than Ohm's Law, you can see and work it out for yourself. Reg, G4FGQ. |
The resistance in the anode circuits of the LEDS only serves as an attempt
at limiting the current through the FWD LED to full brightness (and a constant current source would best replace this)--and to keep it from "burning out." My goals are this: 1) CHEAP!! 2) Cheap! 3) Fewest possible parts... 4) Marginal functionality... I want to be able to cover the world with these devices (put one on every single antenna project of mine (even the EH Antenna!!! grin) I will continue to toy with the design as my time permits.... I am quite willing to suffer the slings and arrows of others, education is expensive yanno!!! And, I do see most, if not ALL, are saying there is much more to SWR than at first it seems... Thanks Reg... Warmest regards, John "Reg Edwards" wrote in message ... | | John (Smith), all you have is a circuit which might light up a couple | of light-emitting diodes from an RF source via a current transformer. | What purpose is served by the 100K resistor is anybody's guess. But it | has nothing to do with SWR. | | As Cecil implies, you should go right back to square one and think | about it. | | Actually, you are in good company. Most people don't know how their | SWR meter works or what it does. Most people and Tx manufacturers | don't connect it in the correct place for it read SWR on the | transmission line. Consequently it doesn't even indicate SWR and its | name is a very misleading misnomer. | | All it indicates is the magnitude of the reflection coefficient of the | load on the transmitter relative to the impedance the transmitter is | designed to see. And it only does THAT provided the meter has itself | been designed to cater for the same impedance. It is fortunate there | exists a standard impedance of 50 ohms. | | But don't allow me to put you off. Just obtain a circuit diagram of a | so-called SWR meter (an HF version) from a handbook and, with little | more than Ohm's Law, you can see and work it out for yourself. | | Reg, G4FGQ. | | |
John Smith wrote:
Well, If there is a voltage, there is a current (albeit, at times very small)--the opposite is also true, ohms law is standing proof... Yes, but the amplitude and phase relationship of current to voltage can have any possible value and there are an infinite number of possibilities. In the equation, Z = V/I, you cannot determine Z unless you know BOTH V and I. Why can't I measure the standing wave ratio as a ratio of power, ... You need both voltage and current to determine power. Your design senses only current. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
OK. Perhaps here the problem lies....
I am looking at it like this: I don't care what value is V, nor what value is I... I care only how much power the antenna is radiating, and how much is "reflected" back and sits on the plates, collectors, or drains and is wasted as heat--develops itself on the feedline--radiates from other antenna components--etc.... I am thinking the "directional coupler" is doing that action, and forcing the amount of "forward" power to one LED (amount of power actually leaving the antenna (allowing for losses)) and giving indication--and the "reflected" to the other LED (the amount of power "wasted") and giving indication... I take for granted that when 'Z' of "output of xmtr" = coax = antenna input, I see the "REF LED" at dark condition.... There WELL may be an error in my thinking and, the "thing" (frankenstein?) I have constructed only "seems" to work... (kinda like time yanno grin) Thanks for your patience Cecil.... Warmest regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | Well, If there is a voltage, there is a current (albeit, at times very | small)--the opposite is also true, ohms law is standing proof... | | Yes, but the amplitude and phase relationship of current to | voltage can have any possible value and there are an infinite | number of possibilities. In the equation, Z = V/I, you cannot | determine Z unless you know BOTH V and I. | | Why can't I measure the standing wave ratio as a ratio of power, ... | | You need both voltage and current to determine power. Your design | senses only current. | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
On Wed, 4 May 2005 11:23:39 -0700, "John Smith"
wrote: The resistance in the anode circuits of the LEDS only serves as an attempt at limiting the current through the FWD LED to full brightness It, in fact, serves to reverse bias the other LED, turning it OFF (until the first LED depletes the capacitor which then reverses the situation - the original RDL flip-flop running asynchronously). Which one lights up is a matter of an indeterminate logic race, not some proportionality of powers. (and a constant current source would best replace this)-- If you think about this statement, you would recognize that either/both LEDs would always be ON and equally bright. [the word "constant" should be a dead give-away] and to keep it from "burning out." Then you put a current limiter (not constant current device) in EACH LED lead (not sharing). To select a 1KOhm limiter presumes a 20V drop across it for a 20mA LED excitation current (a typical current specification). You may achieve the 20mA limit, but it will come at the cost of more than 40V across 100 Ohms backing through the current transformer (it is NOT a directional coupler) which can only be supplied by a transmitter excitation of several KW to a matched load. If you did nothing other than simply connect an LED across the current transformer's terminals and adjust the transmitter for 20mA through the LED, you would need 8W into a matched load. To put it simply, you are fixated on a problem so remote from your goal, that solving it basically accomplishes nothing towards measuring (or even indicating) SWR. As several suggestions have been offered to research a real topology, you might want to pursue that first. 73's Richard Clark, KB7QHC |
John Smith wrote:
I wish an indication of SWR which is cheap, uses fewest parts possible, and has the possibility of "automatic operation" and one can be placed on each and every antenna I am playing with (or anything else, maybe one on the bird fountain! grin)... Got just the device for you on page 520 of "The radio amateur's handbook", 1957 by the ARRL. It's called the "twin-lamp" and consists of a piece of 300 ohm twinlead and two flashlight bulbs. I used one in 1957 on my all-band off-center-fed dipole. I ran 40 watts on 11m in those days. :-) You might want to take a look at another type of design for SWR meters. There is one that uses a short piece of slotted line with two parallel conductors that separate the forward and reflected components without phasor addition/subtraction. Here's a schematic of the Heathkit HM-11 SWR meter. http://www.qsl.net/kb7rgg/heath/sche...chema_hm11.gif Note the low component count. The only tricky part is the slotted line but that is a mechanical problem, not an electronics problem. Resistors R1 and R2 attenuate one wave in one direction leaving the other wave in the other direction to be rectified by d1 and d2. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
John Smith wrote:
I want to be able to cover the world with these devices (put one on every single antenna project of mine (even the EH Antenna!!! grin) http://www.qsl.net/kb7rgg/heath/sche...chema_hm11.gif -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
John Smith wrote:
There WELL may be an error in my thinking ... No, there *IS* an error in your thinking. Blood from a turnip comes to mind. The current in your feedline is one amp. What is the power? See the problem? -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Well, that is how my "meter SWR" which I constructed looks all right--but I
wished to get away having to construct a directional coupler from tubing and pickup loops... Only, my (metered) SWR meter uses just ONE pickup loop, I switch terminating 50 ohm resisistor and take-off ends and use the single loop for BOTH "FWD" and "REF", with a physical switch--my thinking was it would keep the device more "balanced" using the same pickup... Warmest regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | I want to be able to cover the world with these devices (put one on every | single antenna project of mine (even the EH Antenna!!! grin) | | http://www.qsl.net/kb7rgg/heath/sche...chema_hm11.gif | -- | 73, Cecil http://www.qsl.net/w5dxp | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups | ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
For anyone interested, here is the datasheet on the siemens LED,
unfortuantly, mostly in german frown This opens a "prohosting page", a link is given you there to view the ..pdf... sorry Richard H. http://blake.prohosting.com/mailguy2...-LO5436-TO.pdf Regards, John "John Smith" wrote in message ... | This is a SWR bridge I built using leds and a homemade "directional | coupler." | | ALL critiques on it, and ideas for improvements are welcomed!!! | | Please excuse my rough drawing, I am NOT a draftsperson! | | Hopefully, the attachment of the .jpg was successful.... | | Warmest regards, | John | | |
OK. Here is a revision... directional coupler changed, "automatic operation"
added... (and, the .005 caps would be on the ground side of the 1k resistors, at the leds' cathodes!!!) Thoughts? Warmest regards, John "John Smith" wrote in message ... | This is a SWR bridge I built using leds and a homemade "directional | coupler." | | ALL critiques on it, and ideas for improvements are welcomed!!! | | Please excuse my rough drawing, I am NOT a draftsperson! | | Hopefully, the attachment of the .jpg was successful.... | | Warmest regards, | John | | |
I claim Alzheirmers!!!
OK, here is the link: http://blake.prohosting.com/mailguy2/JS-Rev2.jpg Regards, John "John Smith" wrote in message ... | OK. Here is a revision... directional coupler changed, "automatic operation" | added... | (and, the .005 caps would be on the ground side of the 1k resistors, at the | leds' cathodes!!!) | | Thoughts? | | Warmest regards, | John | | "John Smith" wrote in message | ... || This is a SWR bridge I built using leds and a homemade "directional || coupler." || || ALL critiques on it, and ideas for improvements are welcomed!!! || || Please excuse my rough drawing, I am NOT a draftsperson! || || Hopefully, the attachment of the .jpg was successful.... || || Warmest regards, || John || || | | |
Well, obivious errors there, such at the 1k gate resistor should be in the
source path, with the gate returned directly to gnd... etc... But, you get the idea... sketched that TOO quickly... Regards, John "John Smith" wrote in message ... |I claim Alzheirmers!!! | | OK, here is the link: | http://blake.prohosting.com/mailguy2/JS-Rev2.jpg | | Regards, | John | | "John Smith" wrote in message | ... || OK. Here is a revision... directional coupler changed, "automatic | operation" || added... || (and, the .005 caps would be on the ground side of the 1k resistors, at | the || leds' cathodes!!!) || || Thoughts? || || Warmest regards, || John || || "John Smith" wrote in message || ... ||| This is a SWR bridge I built using leds and a homemade "directional ||| coupler." ||| ||| ALL critiques on it, and ideas for improvements are welcomed!!! ||| ||| Please excuse my rough drawing, I am NOT a draftsperson! ||| ||| Hopefully, the attachment of the .jpg was successful.... ||| ||| Warmest regards, ||| John ||| ||| || || | | |
On Wed, 4 May 2005 13:40:47 -0700, "John Smith"
wrote: I claim Alzheirmers!!! OK, here is the link: http://blake.prohosting.com/mailguy2/JS-Rev2.jpg Hi Brett, Another Watt soaker (you better use 5W 50 Ohm resistors if you don't want blisters or burnt LEDs) - that is, if the caps (basically useless) don't turn off the LEDs. You will need to pour the power to a matched load to light them up (very poor low end sensitivity from pretty feeble LEDs). You could as easily throw away all the resistors and caps (and the so-called constant current source), or at least replace the resistors to 1/10 value straight to ground. I thought you wanted cheap? 73's Richard Clark, KB7QHC |
Richard:
Your comments are appreciated, can't get to the bench today... When I do, will keep your suggestions in mind... Thanks Richard... Warmest regards, John "Richard Clark" wrote in message ... | On Wed, 4 May 2005 13:40:47 -0700, "John Smith" | wrote: | | I claim Alzheirmers!!! | | OK, here is the link: | http://blake.prohosting.com/mailguy2/JS-Rev2.jpg | | | Hi Brett, | | Another Watt soaker (you better use 5W 50 Ohm resistors if you don't | want blisters or burnt LEDs) - that is, if the caps (basically | useless) don't turn off the LEDs. You will need to pour the power to | a matched load to light them up (very poor low end sensitivity from | pretty feeble LEDs). | | You could as easily throw away all the resistors and caps (and the | so-called constant current source), or at least replace the resistors | to 1/10 value straight to ground. | | I thought you wanted cheap? | | 73's | Richard Clark, KB7QHC |
Well, I won't even mention my supply of mpf-102's--it is limitless... and
those 1/2 inch toroids too... Regards, John "Richard Clark" wrote in message ... | On Wed, 4 May 2005 13:40:47 -0700, "John Smith" | wrote: | | I claim Alzheirmers!!! | | OK, here is the link: | http://blake.prohosting.com/mailguy2/JS-Rev2.jpg | | | Hi Brett, | | Another Watt soaker (you better use 5W 50 Ohm resistors if you don't | want blisters or burnt LEDs) - that is, if the caps (basically | useless) don't turn off the LEDs. You will need to pour the power to | a matched load to light them up (very poor low end sensitivity from | pretty feeble LEDs). | | You could as easily throw away all the resistors and caps (and the | so-called constant current source), or at least replace the resistors | to 1/10 value straight to ground. | | I thought you wanted cheap? | | 73's | Richard Clark, KB7QHC |
On Wed, 4 May 2005 15:04:41 -0700, "John Smith"
wrote: Well, I won't even mention my supply of mpf-102's--it is limitless... and those 1/2 inch toroids too... A backyard full of coal won't make a diamond. |
Richard:
No. That is correct coal is better, might help a guy keep "getting warm." grin And, that current source works, I have used it many times (makes an excellent test lamp for 5-30V)... will with stand at least 30V+ across drain and source and maintain ~10ma... when the REV current to its' led drops to zero, max flows though the FWD--all other cases they must share that 10ma... Regards, John "Richard Clark" wrote in message ... | On Wed, 4 May 2005 15:04:41 -0700, "John Smith" | wrote: | Well, I won't even mention my supply of mpf-102's--it is limitless... and | those 1/2 inch toroids too... | A backyard full of coal won't make a diamond. |
John Smith wrote:
Well, that is how my "meter SWR" which I constructed looks all right--but I wished to get away having to construct a directional coupler from tubing and pickup loops... Only, my (metered) SWR meter uses just ONE pickup loop, I switch terminating 50 ohm resisistor and take-off ends and use the single loop for BOTH "FWD" and "REF", with a physical switch--my thinking was it would keep the device more "balanced" using the same pickup... A toroidal pickup samples the current at one point. Knowing the current at one point tells you absolutely nothing about SWR. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
I am thinking, that is ok, long as there is none reflected...
Regards, John "Cecil Moore" wrote in message ... | John Smith wrote: | Well, that is how my "meter SWR" which I constructed looks all right--but I | wished to get away having to construct a directional coupler from tubing and | pickup loops... | Only, my (metered) SWR meter uses just ONE pickup loop, I switch terminating | 50 ohm resisistor and take-off ends and use the single loop for BOTH "FWD" | and "REF", with a physical switch--my thinking was it would keep the device | more "balanced" using the same pickup... | | A toroidal pickup samples the current at one point. Knowing the | current at one point tells you absolutely nothing about SWR. | -- | 73, Cecil http://www.qsl.net/w5dxp | | | ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- | http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups | ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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