LT Spice transmission line simulation - factor of 0.5 error? 1

[electricpete]

I am trying to use LT Spice to model simple lossless transmission line behavior.

As a test case, I considered the geometry discussed in:
thread239-293269

Specifically, I tried to recreate the results shown on slide slide 4 of attachment to the current post (which is the same as slide 4 of attachment to my previous post 27 Feb 11 13:12).

The system which is modeled is as follows:
[Vs]-[Rs=1]--===[TL1]===--===[TL2]===-===[TL3]===-[RLoad=1]

Vs is a ramp rise with magnitude 1, duration 1
TL1: Zc=1, length unimportant since source is matched
TL3: Zc=1, length unimportant since load is matched
TL2: Zc=3, length corresponds to transit time of 3. It represents the anomaly in impedance due to ferrite sleeve.

The Maple / analytical solution (same as previouis post) is described on page 2 and the pdf embedded in slide 3. The result is plotted on slide 4 and has the expected behavior that the output voltage eventually rises to the input voltage.

The LT Spice solution is shown on attached slides 5 and 6. It has the same shape, but only rises to magnitude 0.5... which must be wrong. More details on the LT spice model are on slides 7 and 8.

Am I missing something or did the LT spice model computes this result incorrectly? If so, why?

=====================================
(2B)+(2B)' ?

 

[VEBill]

It's not as simple as splitting the Vs between the Rs and the Rload?

(PS: I didn't take the time to review the attachment in detail. It's a bit late.)

 

[electricpete]

Ah, yes. That is it exactly. I put Rs in there to provide matching, but I forgot about it.

Problem solved. Thanks.

=====================================
(2B)+(2B)' ?