| Message |
Date |
From |
Subject |
| 11240
| 2015-06-26 13:36:53
| ve6jf
| Hybrid Cascode IF for 5mHz
|
I think I have at least part of this correct, but at my age I'd rather check before warming up the iron: I am working on a QRP xcvr for 40m loosely based on the "Unfinished" P12.12. (I chose this as a start due to available key components on hand). Aside from incorporating full QSK from the QEX article by Marcus, using the cascode IF is one of a few things I am attempting to do differently, especially since the IF was one area noted as a weak point. Using xmat.exe I believe that the input network L1/C2 should be 12.34uH / 80.68pF for 5mHz. Now I'm reasonably sure this calculation is correct but I wonder if I am missing anything else to transition the circuit to 5mHz that I am unaware of. So far I have most of my other circuit changes working in LTSPICE including the QSK design, but have not yet inputted the IF stage. Thanks for any advice or comments.. 73 Jim Leslie VE6JF FP #1040 QRP-L #2612 QRP Canada #247 NAQCC #5968 SKCC #14108
|
| 11241
| 2015-06-26 14:38:45
| w7zoi
| Re: Hybrid Cascode IF for 5mHz
|
Hi Jim, and gang,
I used ZMAT08.exe and came up with slightly different numbers. I used an L-network to match from 50 Ohms up to 3.3K at 5.0 MHz. I came up with 12.8 uH and 77.7 pF, slightly different than the numbers that you mentioned. You may have been shooting for a slightly lower R.
Good luck with the rig.
73, Wes w7zoi
|
| 11243
| 2015-06-26 15:33:14
| ve6jf
| Re: Hybrid Cascode IF for 5mHz
|
Wes (everyone), That's right; I used a value of 3K based on the errata notes. But after re-reading the errata it dawned on me the change to 3K from 3.3K was most likely to allow for the use of the Mouser 6.8uH RFC rather than the wound 7.1uH one. Hence the value change. I plan to wind my RFC so I will use the 3.3K as per the original Dec 07 QST schematic. I just re-ran it and came up with the values you did.. Thanks for the response, 73 Jim |
| 11244
| 2015-06-26 21:08:17
| K5ESS
| Re: Hybrid Cascode IF for 5mHz
|
Are XMAT.exe or ZMAT08.exe available for download? Google didn’t turn anything up. Thanks, Mike K5ESS
| 11245
| 2015-06-26 21:28:41
| vasilyivanenko
| Re: Hybrid Cascode IF for 5mHz
|
They come on the CD that ships with EMRFD.
|
| 11246
| 2015-06-27 08:59:45
| K5ESS
| Re: Hybrid Cascode IF for 5mHz
|
Well I thought that might be the case but a search of the CD gave no results. My copy of the CD is flawed. The setup.exe file in LADPAC2008 won’t run from the CD saying that it can’t load LADPAC2002.txt, the reason being that the file in the folder is named LADPAC2008.txt. After copying the files to my hard disk and changing the name of LADPAC2008.txt to LADPAC2002.txt the setup.exe file runs OK. However; the LADPAC2008 directory on my CD contains none of the 2008 updated programs and ZMAT08.exe along with several other items listed in the LADPAC2008 User Manual are missing. My copy of EMRFD is the Revised 1st Edition. Do I need to contact ARRL about this? Thanks, Mike K5ESS
| 11247
| 2015-06-27 09:32:52
| vasilyivanenko
| Re: Hybrid Cascode IF for 5mHz
|
Sorry this is happening. Well Wes, monitors this feed, so I don't want to speak for him -- but
perhaps send him a private email for his advice?
|
| 11248
| 2015-06-27 09:52:40
| Jim Smith
| Re: Hybrid Cascode IF for 5mHz
|
Have you tried downloading from here: http://w7zoi.net/emlad08_123.html ? 73 Jim - G3ZQC
| 11249
| 2015-06-27 10:44:13
| Cecil Lindsey
| Re: Hybrid Cascode IF for 5mHz
|
Mike, Here is link to ARRL update. 1. - click 2. Scroll down to EMRFD listing - click 3. Download Ladpac2008 Zip File and follow simple directions All 28 files included, yes ZMA08 is there as well. Cecil NA6RF
| 11250
| 2015-06-27 10:47:48
| K5ESS
| Re: Hybrid Cascode IF for 5mHz
|
Thanks Cecil. Mike K5ESS
| 11251
| 2015-06-27 10:49:02
| K5ESS
| Re: Hybrid Cascode IF for 5mHz
|
Thanks to you too Jim. Mike K5ESS
| 11253
| 2015-06-28 20:15:54
| afu
| Re: Hybrid Cascode IF for 5mHz
|
Hi Jim, I hope you are not meaning what you have written ! 5 mHz means 0.005Hz........... what you meant was either 5MHz or for Spice 5MegHz ?! The lower case m means milli the upper case M Mega ! Herbert Am 26.06.2015 21:36, schrieb ve6jf@yahoo.com [emrfd]: I think I have at least part of this correct, but at my age I'd rather check before warming up the iron: I am working on a QRP xcvr for 40m loosely based on the "Unfinished" P12.12. (I chose this as a start due to available key components on hand). Aside from incorporating full QSK from the QEX article by Marcus, using the cascode IF is one of a few things I am attempting to do differently, especially since the IF was one area noted as a weak point. Using xmat.exe I believe that the input network L1/C2 should be 12.34uH / 80.68pF for 5mHz. Now I'm reasonably sure this calculation is correct but I wonder if I am missing anything else to transition the circuit to 5mHz that I am unaware of. So far I have most of my other circuit changes working in LTSPICE including the QSK design, but have not yet inputted the IF stage. Thanks for any advice or comments.. 73 Jim Leslie VE6JF FP #1040 QRP-L #2612 QRP Canada #247 NAQCC #5968 SKCC #14108
|
| 11254
| 2015-06-28 21:09:14
| ve6jf
| Re: Hybrid Cascode IF for 5mHz
|
Hi Herbert, Nice catch! 73 Jim ....I should have also specified zmat.exe, not xmat. :) ---In emrfd@yahoogroups.com, wrote :
Hi Jim,
I hope you are not meaning what you have written !
5 mHz means 0.005Hz........... what you meant was either 5MHz or for Spice 5MegHz ?!
The lower case m means milli the upper case M Mega !
Herbert
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