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authorAndreas Eversberg <jolly@eversberg.eu>2016-10-02 09:01:12 +0200
committerAndreas Eversberg <jolly@eversberg.eu>2016-10-02 09:06:06 +0200
commit50e311590ae595d723827ccd18b6be2d274699fa (patch)
treec88117aea143b388f6ff6241d3f47d8db585d5a9 /docs
parentb07509cf2d480b16fbc5e15a8459256badef2d9c (diff)
work on docs
Diffstat (limited to 'docs')
-rw-r--r--docs/amps.html10
-rw-r--r--docs/nmt.html10
2 files changed, 14 insertions, 6 deletions
diff --git a/docs/amps.html b/docs/amps.html
index a295482..1720081 100644
--- a/docs/amps.html
+++ b/docs/amps.html
@@ -23,6 +23,12 @@ History
<p>
*TBD*
+
+The Advanced Mobile Phone Service (AMPS) was an analog cellular mobile phone system developed by Bell Labs.
+From 1968 to 1983 the Bell Labs worked out the system, while Motorola was developing the cellular phone.
+Dr. Martin Cooper produced the first handheld phone "DynaTAC8000x", the famous Brick Phone.
+
+
</p>
<center><img src="amps-dynatac.jpg"/></center>
@@ -61,8 +67,8 @@ History
<p>
To reduce radio noise, a syllabic compandor is used on both ends.
This compresses the audio level dynamics by 2.
-An audio level of 25% is raised to 50% by the compressor and lowered to 25% by the expandor.
-A radio noise floor of 10% would be reduced to 1% by the expandor.
+An audio level of 25% is raised to 50% by the compressor and lowered to 25% by the expander.
+A radio noise floor of 10% would be reduced to 1% by the expander.
</p>
<p class="toppic">
diff --git a/docs/nmt.html b/docs/nmt.html
index 669ff97..f666547 100644
--- a/docs/nmt.html
+++ b/docs/nmt.html
@@ -621,11 +621,13 @@ The phone stores the new traffic area and acknowledges the release request.
<p>
Level adjustment:
We see a receive level of around 182%.
-Tune your receiver to the up-link frequency, so you get loop-back of base station broadcast.
-Use the variable resistor (connecting your transmitter) to adjust the volume until the received level matches the same level of your previously received bust.
+Tune your receiver to the donw-link frequency, so you get loop-back of base station broadcast.
+Use the variable resistor connecting your transmitter, to adjust the volume until the received level matches the same level you previously received from the phone.
In my case I adjust the transmitter to match around 182%. (+- 10% is good)
-Now, whatever frequency deviation the phone transmits for signaling, so does your base station. Use the other variable resistor (connecting your receiver) to adjust the volume until the level matches about 100%. (+- 10% is good)
-Switch back the receiver to up-link frequency and change the traffic area to see the result of your adjustment.
+Now, whatever frequency deviation the phone transmits for signaling, so does your base station, because you receive the same level from your base station as you did from the phone.
+Use the other variable resistor connecting your receiver, to adjust the volume until the level matches about 100%. (+- 10% is good)
+Now, your base station receives the correct frequency deviation as 100%. Also voice levels are now adjusted right.
+Switch back the receiver to up-link frequency and change the traffic area to see the result of your adjustment as the phone registers.
</p>
<p>