Specifications
•
Ver ti cal Dis play: 10 dB/Div
•
Sweep: Auto
•
Peak/Avg: Peak
•
Ref er ence Level: 30 dBm
• Time/Div: 20ms
Ad just the ref er ence am pli tude to place
the peak of the car rier slightly above the
top graticule line.
En able the “fine” am pli tude ad just ment.
Set the car rier peak to ex actly the top of
the ref er ence line.
Read the dis played am pli tude.
Re peat for the 243.0 MHz har monic
(Change the “Cen ter Fre quency” to 243.0
MHz. All other set tings re main the same).
The min i mum al lowed am pli tude on
121.5 MHz and 243.0 MHz is 23 dBm
(200 mW).
4.3.8 (Step 5c) 121.5 MHz Fre-
quency
The ELT trans mit ter fre quency may be
mea sured as fol lows:
Con nect the fre quency coun ter as shown
be low:
If the 121.5 MHz car rier fre quency is
within spec i fied pa ram e ters, the 243.0
MHz fre quency will also be within spec i -
fied pa ram e ters.
The ELT should be within 50 ppm (+/-
6.075KHz) of 121.500000 MHz.
4.3.9 (Step 5d) Au dio Mod u la-
tion
Dur ing the swept tone por tions the au -
dio should “sound” like an ELT. Set the
unit switch to the “OFF” po si tion.
4.3.10 (Step 5e) Mea sure
406.025 MHz Power
Note: the power out put is ap prox i mately
37 dBm @ 5 Watts. En sure ad e quate at-
ten u a tion is in serted in-line be tween the
ELT’s 406.025 MHz out put and the in put
to the spec trum an a lyzer to pro tect the
an a lyzer’s in put cir cuitry.
Con nect the equip ment as shown be low:
Set the Spec trum An a lyzer as fol lows:
•
Cen ter Freq: 406.025 MHz
•
Span: 1 MHz
•
Res o lu tion Band width: 1 MHz
•
Ver ti cal Dis play: 10dB/Div
•
Sweep: Auto
• Peak/Avg: Peak
•
Ref er ence Level : 30 dBm
• Time/Div: 20ms
• Max Hold: On
• At tenu ator (as re quired) on In put
Turn the ELT on and wait approxi-
mately 50 sec onds for the 406.025 MHz
trans mit ter to turn on (trans mit ter sends
out first sig nal at 50 sec onds then ev ery
50 sec onds there af ter). De ter mine the
power out put from the stored wave form.
The 406.025 MHz power out put should
ARTEX AIRCRAFT SUPPLIES DOCUMENT # 570-5000
04/11/01 PAGE 4-6
SPECTRUM
ANALYZER
Applicable
Attenuator
ELT
TPS (Bottom)
Connector
Frequency
Counter
ELT
BNC (Top)
CONNCTOR