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- Instructions for the MATCH.EXE resonant Z-matching networks.
-
- The program MATCH.EXE for PC-type computers is used in a Windows GUI
- environment to design the 14 NBMATCH networks that ARRL has been
- publishing for many years in such publications as the Handbook and the
- UHF/Microwave Experimenter's Handbook. These very useful networks are
- described in the 2005 and later ARRL Handbooks in Chapter 14.
-
- The new program corrects some errors that were found in the original
- BASIC programs, NBMATCH.BAS and NBMATCH.EXE. It is also much more
- convenient to operate. All 14 networks have been verified, using the
- new MATCH.EXE.
-
- MATCH.EXE is a Visual Basic V5.0 program. It is about 26K in size, and
- requires the file Msvbvm50.dll (1324K) to reside in the Windows\System
- folder. This is a standard file (public domain) for Windows 98 and is
- also on the '98 System compact disk. Both files should be downloaded
- from the ARRL website for use on '95 Systems.
-
- The usage is pretty much self-explanatory. Select a network, input the
- values of RS, RL and F0. The value of Q (selectivity) is requested,
- which must be greater than the minimum value that the text window
- indicates. Networks 13 and 14 have a fixed value of Q which cannot be
- modified. The L and C values are calculated, after which two courses of
- action can be taken: 1) Modify RS, RL, F0, and Q or 2) Select a
- different network. In all cases the main text window gives instructions
- for the next action.
-
- The ouput of MATCH.EXE is the three L and C values for the network,
- based on user inputs. These values can then be transferred manually to
- such programs as ARRL Radio Designer or SPICE or other analysis programs
- to get frequency and phase responses and also attenuation due to L and C
- component losses.
-
- An improvement to the program involves the Q value. One measure of Q is
- the selectivity, which is defined as approximately the ratio of the center
- frequency to the 3 dB bandwidth. The Q in MATCH.EXE is a parameter that
- is used for network design purposes and does not in every case represent
- the actual selectivity. The improved version asks the user to input the
- actual Q (selectivity) that is desired. The program output gives a value
- of Q that is the actual value. If the *actual* value is different than
- the *desired* value, modify the input value in the proper direction.
- The L and C values are then correct for the desired selectivity.
- Often the difference is not critical, but if the true selectivity
- is important, this procedure is helpful.
-
- The displayed Q value pertains to a network that is resistively loaded
- *only* at one end. This is a standard procedure for networks of this kind.
- If the network is counjugately loaded at both ends the Q is one-half the
- singly-loaded value. If this other end is loaded, but not conjugately loaded,
- it is best to simulate and revise the network iteratively, using MATCH.EXE,
- to get the required selectivity. Also, the amount of loading of the network
- has a small effect on the resonant frequency that should be checked by
- simulation.
-
- A "singly-loaded" network means the following:
-
- A) For networks 1,2,3,4,9,10,11,12,13,14, RL is very large
- B) For networks 5,6,7,8, RS is very small.
-
- Questions regarding the program can be e-mailed directly to me:
-
- William E. Sabin W0IYH
- 1400 Harold Dr., S.E.
- Cedar Rapids IA 52403
- w.sabin@mchsi.com
-