EMRFD Message Archive 9659

Message Date From Subject
9659 2014-01-17 13:01:26 Phil Sittner SA612 spice model
Does anyone have experience with working with a spice model for SA612? I'd appreciate any input you may have on the subject.
 
Phil
kd6rm
9690 2014-02-02 21:44:11 drmail377 Re: SA612 spice model

Hi Phil,


I have what purports to be an SA612 model for LTSpice sent to me by W3JDR back in February of 2010.


Unfortunately I have no idea how to contact you outside this Group. There used to be a way to send a message poster and Email. But I don't see that option in this new-fangled user Yahoo Group user interface.


I reticent to post files in the Files area. Any suggestions?


Best 73's, David WB4ONA

9695 2014-02-03 16:50:49 Phil Sittner Re: SA612 spice model

David-
 
Thank you for the helpful response. I have issues with the new interface as well and have nothing to offer in the way of advice for navigating it. You can send it to my email address: sittners@sbcglobal.net. Have you tried the model and do you have any suggestions for it's use?
 
Phil
kd6rm
----- Original Message -----
9698 2014-02-07 07:51:27 drmail377 Re: SA612 spice model
Hi Phil, Thanks for the Email link. I'm in Jakarta and it is getting late my time (UTC+7 Friday). I'll package up what I have tomorrow my time and email it to you with some additional comments.

73's David
9699 2014-02-07 15:47:06 Phil Sittner Re: SA612 spice model

Thanks David, and there's no need to rush.
 
Phil
----- Original Message -----
9700 2014-02-08 05:23:39 drmail377 Re: SA612 spice model
Hi Phil,

At closer examination, your post with your Email link is still not fully revealed in your post here. So that's not going to work. Anyway, I uploaded the model archive to a public repository. Here are some instructions to download etc. The file won't be there for download forever, so have at it while the getting is good...

To download:

1. Go to the link below:

http://www.datafilehost.com/d/21d45e10

You should see:

File: SA612 LTSpice Model Rev 04.zip
Size: 7.97 KB

2. REMOVE the check-mark next to "Use our download manager and get recommended downloads".

3. Next click the GRAY "DOWNLOAD" button, NOT the big DOWNLOAD NOW button.

4. The download should start, save to your HDD.

Note: The uploaded file will remain for 30 or 60 days (can't remember which) after the last download. I'll leave the file up for awhile before deleting it. The file is not mine. The original Author is cited in the "Readme.txt" file contained in the archive. I don't see any copyright or license info in the files at first glance, so this archive is a bit of an enigma. I have not rigorously tested this simulation.

To use the simulation:

Unzip the .zip archive into a separate directory, keep all the files together. There is a test jig called "NE602 Rx.asc" which is an example 20m receiver, LTSpice should start and show the jig schematic. Run the simulation.

Note: Read the file "Readme.txt" in the archive. Also, the test jig "NE602 Rx.asc" (not authored by me) is set up by default as an AC simulation. You might want to change this to a transient simulation to see the audio output etc.

Let me know how the simulation works out for you.

Best 73's David
9701 2014-02-08 05:59:06 drmail377 Re: SA612 spice model
Further clarification on invoking the transient simulation instead of the default AC simulation:

1. Open the original "NE602 Rx.asc" file in LTSpiceIV (you may want to save it under a different name first).

2. At the bottom of the schematic you will see two lines:

.ac lin 200 10e6 20e6
;tran 100usec

Change these two lines one at a time by doing the following:

Ctrl+right-click the line:

.ac lin 200 10e6 20e6

Edit the line to look like this (add preceding ";"):

;.ac lin 200 10e6 20e6

Ctrl+right-click the line:

;tran 100usec

Edit the line to look like this (remove preceding ";" and add a "." in front of the directive "tran"; the original AUthor neglected to include the preceding "." in the default test jig schematic):

.tran 100usec

So after editing the two lines look exactly like this:

;.ac lin 200 10e6 20e6
.tran 100usec

Run the simulation, the waveform view window should pop-up with nothing shown. Wait for the simulation to finish.

Now click the schematic view window and click on the "Audio Out" label at the output of U1.

You should see a 20KHz sine wave. This is the demodulated audio out. Read the original Author's comments at the top of the schematic to understand what is going on in the simulation.

You can reverse the above steps to return the simulation to AC mode. Just put a ";" in front of the ".tran" directive to comment it out and remove the ";" in front of the .AC directive to activate AC mode. Note: there are other ways to do this in LTSpice, but I won't go into that here.

73's David