Daniels VT-3H040 Kullanım Kılavuzu - Sayfa 12

Verici Daniels VT-3H040 için çevrimiçi göz atın veya pdf Kullanım Kılavuzu indirin. Daniels VT-3H040 13 sayfaları. Vhf transmitter

unless it is confirmed that the original and replacement synthesizer have identical output power

(within ± 0.5 dBm).

2.3.4

Deviation Setting

The transmitter maximum deviation range is set by jumpers at the factory to ± 5.0 kHz for the

VT-3H040 transmitter. However, under some conditions such as a large change in transmitter

operating frequency, the deviation control may need adjustment. The transmitter deviation is

dependent on the operating frequency and this dependency is likely to be more severe at the band

edges. For frequency changes exceeding ± 0.5 MHz, especially at the band edges, the deviation

should at least be checked and corrected if necessary. See the Audio Processor section of the

Transmitter Main Board Manual for details on setting the transmitter deviation. Note that the

adjustment of the balance compression levels, which is also discussed in the Audio Processor

alignment section, is not required as this adjustment should not be affected by a change in

frequency or deviation settings.

2.3.5

Setting RF Alarm Thresholds

The VSWR and Forward Power Alarms are factory preset to give alarm conditions for a 3:1

VSWR and 50 % forward power respectively. The Amplifier Manual describes how to adjust

these settings, should different levels be required. If the alarm thresholds are crital to operation

of a particular installation and if the transmitter undergos a large change in frequency (see section

2.3.2 above), the threshold alarm levels, particularly the VSWR alarm, should be checked.

2.4

Recommended Test Equipment List

Alignment of the transmitter requires the following test equipment or its equivalent.

Dual Power Supply:

Oscilloscope / Multimeter:

Current Meter:

Radio communications test set :

VSWR 3:1 mismatch load:

Alignment Tool:

It is recommended that the radio communications test set be frequency locked to an external

reference (WWVH, GPS, Loran C) so that the high stability oscillator may be accurately set to

within its ±1 ppm frequency tolerance.

DANIELS

ELECTRONICS

VT-3H040 VHF Enhanced Transmitter Instruction Manual

Regulated +9.5 Vdc at 2 A.

Regulated +13.8 Vdc at 2 A - Topward TPS-4000

Fluke 97 Scopemeter

Fluke 75 multimeter

Marconi Instruments 2955R

JFW 50T-035-3.0:1

Johanson 4192

2-5