Here is some info on the GE version ...maybe it will help ?
73 John VE3AMZ
----- Original Message -----
From: "travis8303" <[email protected]>
To: <[email protected]>
Sent: Sunday, May 09, 2010 6:07 PM
Subject: [Repeater-Builder] Re: Decibel Z-Matcher Replacement Feed-Thru?
> If anyone can help out with this feed thru part, I have the same issue and
> need one as well.
>
> Thanks,
> Travis
> AA9NV
>
> --- In [email protected], "k7icu" <k7...@...> wrote:
>>
>> I have a sick Decibel DB4330 Z-Matcher with a crushed and mangled
>> feed-thru "capacitor" (looks more like a ceramic non-capacitor feed-thru
>> to me). Anyone know if the original feed-thru part is still available
>> out there? Rough details: 10-32 x 3/8" body; 1" long 15 AWG wire ;
>> ceramic insulator; 0.22" mounting hole; 5/16" flat hex-shaped outside
>> end and a 10-32 nut inside the box.
>>
>> James K7ICU
>>
>
>
>
>
> ------------------------------------
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Title: Z-Match
GE
Mastr II Z-Match
The Z-match is
shown on many duplex power amp schematics in many LBI's. The scans below
came from a UHF book, LBI130201, but the information is identical to the
information I found in several others, including VHF pages.
These are the
tuning instructions, quoted directly from the GE document:
"Antenna Matching Unit
Adjustment
The Antenna Matching Unit is used only in continuous
duty duplex stations to optimize impedance matching between the power
amplifier and the load. It consists of a Pi network (C2-C5 and L1) and a
reverse directional coupler. RF from the low pass filter is applied to the
Pi network through the reverse directional coupler and then to the
duplexer load. The reverse directional coupler permits monitoring the
reflected power.
1. Connect DC Voltmeter
across TP1 and ground.
2. Tune C2 and C4 for
minimum voltage as indicated on DC Voltmeter.
3. Push L1 toward or away
from the filter cover wall to further reduce the DC voltage.
4. Repeat steps 2 and 3 as
necessary to obtain an absolute minimum voltage
reading.
Note: The residual voltage
reading after tuning may vary from one transmitter to the next depending
on output power level, operating frequency, and load".
(click the small pictures to see a larger picture in a new
browser window)
VHF
Z-Match
UHF
Z-Match
Z-Match
Schematic. Caution, this opens a large .jpg
Z-Match
Board layout. Caution, this opens a large .jpg
Z-Match
parts list. Caution, this opens a large .jpg
