Home |
Search |
Today's Posts |
#11
|
|||
|
|||
"Wes Stewart" wrote in message
... On Fri, 30 Apr 2004 16:41:06 -0500, "John" wrote: |Yes, I do. I figured you might. I scanned it into pdf, but to get decent quality the file is huge and I only have dialup service at about 26 kB. (Where is that BPL [g]) I'll put it on my web site later when I have a couple of hours free if you want it. Wes I see you have already put it there. I have the same type of service, but I can let it download all night, if necessary. I'm off to get it. Thank you profusely. John |
#12
|
|||
|
|||
"Wes Stewart" wrote in message ... wrote: I figured you might. I scanned it into pdf, but to get decent quality the file is huge and I only have dialup service at about 26 kB. (Where is that BPL [g]) I'll put it on my web site later when I have a couple of hours free if you want it. Wes Wes - I got it. I read it. It did not occur to me that I must short the load to get the phase reference (although it should have). The paper clarifies lots of things for me. I don't have a line stretcher (I though this was a joke when it was mentioned on this forum). However, it appears I can do without it if I recalibrate the phase offset for each change in frequency. I will probably be mostly interested in single-frequency measurements anyway. After you mentioned it, I searched the Web for this app note and was unsuccessful. Thanks ever so much for making it available to me. 73, John - KD5YI |
#13
|
|||
|
|||
On Sat, 1 May 2004 09:00:57 -0500, "John"
wrote: | |"Wes Stewart" wrote in message .. . | wrote: | | I figured you might. I scanned it into pdf, but to get decent quality | the file is huge and I only have dialup service at about 26 kB. | (Where is that BPL [g]) | | I'll put it on my web site later when I have a couple of hours free if | you want it. | | Wes | | |Wes - | |I got it. I read it. It did not occur to me that I must short the load to |get the phase reference (although it should have). The paper clarifies lots |of things for me. | |I don't have a line stretcher (I though this was a joke when it was |mentioned on this forum). However, it appears I can do without it if I |recalibrate the phase offset for each change in frequency. I will probably |be mostly interested in single-frequency measurements anyway. | |After you mentioned it, I searched the Web for this app note and was |unsuccessful. Thanks ever so much for making it available to me. No problem, glad you can use it. I have used the technique shown in figure 11. I happen to have all of that stuff. It is really just a resistance bridge and could be duplicated for a lot less money. I have also developed a simple-minded Excel sheet to do the math for the bridge method. If you're interested, www.qsl.net/n7ws/8405.xls 73, Wes |
#14
|
|||
|
|||
On Thu, 29 Apr 2004 02:17:12 GMT, "The other John Smith"
wrote: I presume your source offers a 50 Ohm output Z. There is nothing like a mismatched source looking at a mismatched load to increase confusion by the square. What is the output impedance of an amateur transmitter? I see arguments all the time about this. And even so, what will be the result if it is not matched? If there are reflections from the source, it will show up in the composite forward voltage which will be the reference anyway. Is this not so? Hi John, By virtue of Wes' providing you a copy of AN 77-3 and to further offer you disclosure on the significant contributors of error, consider: http://metrologyforum.tm.agilent.com/download.shtml As part of the suite of calculators of error offered there, you will find the answer to your question above. The "arguments" that you have so closely observed are fundamentally forced naivete (much too long in the tooth to be taken seriously). This is simply the consequence of armchair debate squirming in the face of experience. ;-) 73's Richard Clark, KB7QHC |
#15
|
|||
|
|||
On Sat, 1 May 2004 09:00:57 -0500, "John"
wrote: I don't have a line stretcher (I though this was a joke when it was mentioned on this forum). Hi John, Wait till you hear the one about the sliding load.... 73's Richard Clark, KB7QHC |
#16
|
|||
|
|||
"Wes Stewart" wrote in message ... |After you mentioned it, I searched the Web for this app note and was |unsuccessful. Thanks ever so much for making it available to me. No problem, glad you can use it. I have used the technique shown in figure 11. I happen to have all of that stuff. It is really just a resistance bridge and could be duplicated for a lot less money. I have also developed a simple-minded Excel sheet to do the math for the bridge method. If you're interested, www.qsl.net/n7ws/8405.xls 73, Wes I got it, Wes. Thanks. I'll play with it sometime tonight, I hope. John |
#17
|
|||
|
|||
"Richard Clark" wrote in message ... On Sat, 1 May 2004 09:00:57 -0500, "John" wrote: I don't have a line stretcher (I though this was a joke when it was mentioned on this forum). Hi John, Wait till you hear the one about the sliding load.... 73's Richard Clark, KB7QHC Well... it sounds funny. Maybe it's the way you put it. (snicker) |
#18
|
|||
|
|||
Yikes!
"Wes Stewart" wrote in message ... On Sat, 1 May 2004 09:00:57 -0500, "John" wrote: ....[snip...] | |I don't have a line stretcher (I though this was a joke when it was |mentioned on this forum). Oh my! I figured any jokes I make would be obvious. I used it lately for setting up a switched antenna TDOA DF system. Really nice tool for such things. -- 73, Steve N, K,9;d, c. i My email has no u's. |
#19
|
|||
|
|||
"Wes Stewart" wrote in message ... [...snip...] I have also developed a simple-minded Excel sheet to do the math for the bridge method. If you're interested, www.qsl.net/n7ws/8405.xls 73, Wes Nice spreadsheet, Wes. I use them for everything. Never used the ISBLANK...will now. -- Steve N, K,9;d, c. i My email has no u's. |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
SWR will change with Source Z if you measure AT the Source | Antenna |