/Built/L23HP.doc
8
12/27/2017
install IC2, if a chip resistor in its position, it will need to be removed. R13 (the TXIF gain control)
will then need to be re-adjusted for the correct drive level..
IMPORTANT NOTE:
When re-testing, do not assume that since your output power of the
transverter is low that it is because you do not have enough IF drive. Please consult DEMI if you
have problems obtaining full output power with your new specified drive level.
Common or Split RF connections:
The RF connections may be reconfigured at any time. If you
desire a separate TX and RXRF connection, install a type “N” connector in the RX hole on the end
panel and connect a coax from it to the point on the board between C9 and the LNA board. The
shield is connected to the exposed metal on ground. Then remove C9. This connection does not
have a DC path to ground to bleed static but it is assumed that if you desire a separate RFRX
connection, you have external protection devices installed. The TXRF (ANT/TX) line remain as it
is. If you have separate ports and wish to make them common, reverse the procedure adding C9
and re-installing L2 if it was removed.
Sequencer:
Step 1 +12VDC on RX for a preamp @ 750 mA maximum
The sequencer in the transverter is ready for operation as specified on the front cover
sheet. Its configuration may be changed at anytime. The transverter is keyed on the 4
th
and last
step. It is wired to the #4 point on the circuit board in the sequencer section. This is a “LOW” on
transmit. The other connections are indicated on the front page and wired to the AUX connector
with color code.
Step 2 +12VDC on TX for a TR relay (around the preamp) @ 750 mA maximum
Step 3 Ground on TX to key a HP power amplifier. Sinks 100 mA maximum
Step 1 and 2: They can be connected to switch higher DC voltages. The DC voltage is applied to
the DC1 and DC2 connections on the board (30VDC maximum).
Optional Sequencer Connections:
Step 2: TL2 is a secondary connection to the second step. It is a “LOW” on transmit. It can be
used to drive a relay or key an amplifier but an external isolation device should be utilized.
Caution!
It will sink 50 mA maximum
Step 3 and Step 4: They have secondary outputs that are both “High” on transmit. They are
labeled PH3 and PH4. These should be isolated from devices that require high currents and are
intended to drive low current devices or Pass transistors or FETs. They will source 50mA.
Sequencer Bypassing:
The transverters sequencer may be by-passed to eliminate switching
time delays but is only recommended if it is to be used without any other system components such
as LNAs or power amplifiers. In this case the external PTT input of the transverter, Pin 5 of the
AUX connector may be connected directly to the Amplifier’s PTT input (see component placement
document) between CR9 and C33 labeled PTT-L if using a signal to Ground to key the transverter
or to the PTT-H near R22 if positive voltage keying is utilized. If you bypass the sequencer,
remove the wire coming from the “4” position of the sequencer.
Mast Mount Preamplifier (LNA) Switching:
Provisions have been made to provide DC bias
and switching of a mast mount LNA either directly on the ANT or RF RX coax or through the AUX
connector. Step 1 of the sequencer is utilized for any LNA. A fused line is also be implemented.
The socket for the fuse is located under the DIGILO synthesizer board. Remove the two screws
holding the board in place and install a fuse of up to 2 Amps. A 1 Amp fuse is provided (not
