Albrecht_AE-497S_12W_sch.pdf

Servicemitteilung AE 497 497-U2.PDF 10. 2. 99 1. Verbesserung der S-Meter Linearitt und der Squelch-Empfindlichkeit Problem: Die S-Meter Schaltung der AE 497 S zeigt bei vielen Gerten im unteren Bereich unter 20 dBV Eingangsspannung zu wenig an. Die Squelchempfindlichkeit (Schaltpunkt bei hchster Empfindlichkeit) wird manchmal als zu gering (Schaltpunkt zwischen 8-12 dBV) bemngelt. Abhilfe: Diode D 5 (Original 1 N 4148) durch eine Germaniumdiode 1 N 60 ersetzen. Es ist auch mglich, die Originaldiode in der Schaltung zu belassen und eine Germaniumdiode von oben zustzlich aufzulten. Diese nderung verbessert den Squelch-Schaltpunkt um 4-6 dB und korrigiert die S-Meter-Anzeige im Bereich zwischen S 1 und S 5. Die Diode findet man links unter der FM-Zusatzplatine. Die Zusatzplatine kann man zum Einlten der Diode vorsichtig an den stehenden Verbindungspfosten etwas nach rechts wegdrcken, damit man an D 5 herankommt. User information for Albrecht 10 m transceivers Frequency extension to 454 Channel system All our 10 m all mode transceivers AE 485 S, AE 497 S and AE 201S can be switched temporarily from frequency mode 28-29.7 MHz into channel mode. The list of frequencies and channels can be found on the next page. After the conversion, the radio can be used from 25.165 MHz to 29.695 MHz. While Albrecht specifications are only valid for the amateur range starting with 28.000 MHz, Albrecht cannot guarantee correct operation on extended frequencies, especially on the lower channels. It may happen that the transceiver operate with less performance (output and sensitivity) or does even not lock in on all frequencies outside of the specified amateur radio range. Note: Only authorized users are allowed to operate on these frequencies! Even if You should have a valid amateur radio operators licence it is not allowed to use channels or frequencies outside of the dedicated amateur radio band. The regulations may cary from country to country. Users are requested to fullfill all national user requirements for operating the radio. Switching to 454 CHANNEL MODE: AE 201 S: Just press FUNCTION button, then press CALL and hold this key pressed for about 3 seconds. Release button and the unit works on 454 Channels until the radio will be later switched off again. If You have once switched to 454 channels, You can also toggle between channel number and frequency display by pressing FUNCTION + CALL, but this only by touching the call button for short time. AE 495 S and AE 497 S: same procedure, but here the correct buttons are the FUNCTION and the 2 buttons. Frequeny table for AE 497 S, AE 485 S and AE 201 S in activated channel mode Channel numberBand ABCDEFGHIJ 125.16525.61526.06526.51526.96527.41527.86528.31528.76529.215 225.17525.62526.07526.52526.97527.42527.87528.32528.77529.225 325.18525.63526.08526.53526.98527.43527.88528.33528.78529.235 3A25.19525.64526.09526.54526.99527.44527.89528.34528.79529.245 425.20525.65526.10526.55527.00527.45527.90528.35528.80529.255 525.21525.66526.11526.56527.01527.46527.91528.36528.81529.265 625. 22525.67526.12526.57527.02527.47527.92528.37528.82529.275 725. 23525.68526.13526.58527.03527.48527.93528.38528.83529.285 7A25.24525.69526.14526.59527.04527.49527.94528.39528.84529.295 825. 25525.70526.15526.60527.05527.50527.95528.40528.85529.305 925. 26525.71526.16526.61527.06527.51527.96528.41528.86529.315 1025.27525.72526.17526.62527.07527.52527.97528.42528.87529.325 1125.28525.73526.18526.63527.08527.53527.98528.43528.88529.335 11A25.29525.74526.19526.64527.09527.54527.99528.44528.89529.345 1225.30525.75526.20526.65527.10527.55528.00528.45528.90529.355 1325.31525.76526.21526.66527.11527.56528.01528.46528.91529.365 1425.32525.77526.22526.67527.12527.57528.02528.47528.92529.375 1525.33525.78526.23526.68527.13527.58528.03528.48528.93529.385 15A25.34525.79526.24526.69527.14527.59528.04528.49528.94529.395 1625.35525.80526.25526.70527.15527.60528.05528.50528.95529.405 1725.36525.81526.26526.71527.16527.61528.06528.51528.96529.415 1825.37525.82526.27526.72527.17527.62528.07528.52528.97529.425 1925.38525.83526.28526.73527.18527.63528.08528.53528.98529.435 19A25.39525.84526.29526.74527.19527.64528.09528.54528.99529.445 2025.40525.85526.30526.75527.20527.65528.10528.55529.00529.455 2125.41525.86526.31526.76527.21527.66528.11528.56529.01529.465 2225.42525.87526.32526.77527.22527.67528.12528.57529.02529.475 2325.45525.90526.35526.80527.25527.70528.15528.60529.05529.505 2425.43525.88526.33526.78527.23527.68528.13528.58529.03529.485 2525.44525.89526.34526.79527.24527.69528.14528.59529.04529.495 2625.46525.91526.36526.81527.26527.71528.16528.61529.06529.515 2725.47525.92526.37526.82527.27527.72528.17528.62529.07529.525 2825.48525.93526.38526.83527.28527.73528.18528.63529.08529.535 2925.49525.94526.39526.84527.29527.74528.19528.64529.09529.545 3025.50525.95526.40526.85527.30527.75528.20528.65529.10529.555 3125.51525.96526.41526.86527.31527.76528.21528.66529.11529.565 3225.52525.97526.42526.87527.32527.77528.22528.67529.12529.575 3325.53525.98526.43526.88527.33527.78528.23528.68529.13529.585 3425.54525.99526.44526.89527.34527.79528.24528.69529.14529.595 3525.55526.00526.45526.90527.35527.80528.25528.70529.15529.605 3625.56526.01526.46526.91527.36527.81528.26528.71529.16529.615 3725.57526.02526.47526.92527.37527.82528.27528.72529.17529.625 3825.58526.03526.48526.93527.38527.83528.28528.73529.18529.635 3925.59526.04526.49526.94527.39527.84528.29528.74529.19529.645 4025.60526.05526.50526.95527.40527.85528.30528.75529.20529.655 4129.665 4229.675 4329.685 4429.695 2. Verbesserung des FM Empfangs Problem: Bei FM treten oft NF-Verzerrungen im Empfang auf, besonders wenn die Gegenstation erhhten Frequenzhub benutzt. Sehr oft wird vergessen, da bei FM und AM der Clarifier ebenfalls bettigt werden kann. Normalerweise sollte der Regler in Mittelstellung stehen. In manchen Fllen wird der FM Empfang besser, wenn der Clarifier in einer der beiden Endstellungen steht. In diesem Fall ist wahrscheinlich die FM Platine nicht optimal eingestellt. Abhilfe: Besonders kritisch ist die Abstimmung von CT 10 und L 17. Diese Abgleichpunkte sollten gegeneinander mehrfach nachgestimmt werden, bis das Optimum erreicht ist. Mit einem mit 2 kHz Hub und 1 kHz modulierten Mesendersignal und einem SINAD Meter kann man durch sorgfltiges Abstimmen von CT 10 und L 17 Klirrfaktoren bis unter 3 % entspr. 30 dB SINAD (bewertet) erzielen. Bei 1.5 kHz Hub kann ein Sinadwert von bis zu 40 dB im optimalen Fall erreicht werden. Wenn kein SINAD-Meter vorhanden ist, gengt auch Abgleich nach Gehr oder mit Oszilloskop auf beste Sinusform. Der Abgleich ist optimal, wenn die FM Qualitt sich beim Verstellen des Clarifiers nach beiden Endpunkten in etwa gleichermaen verschlechtert. Die Spulenkerne L47 und L 16 beeinflussen sich untereinander kaum und knnen jeder fr sich auf optimales SINAD eingestellt werden. Frequeny table for AE 497 S, AE 485 S and AE 201 S in activated channel mode Channel numberBand ABCDEFGHIJ 125.16525.61526.06526.51526.96527.41527.86528.31528.76529.215 225.17525.62526.07526.52526.97527.42527.87528.32528.77529.225 325.18525.63526.08526.53526.98527.43527.88528.33528.78529.235 3A25.19525.64526.09526.54526.99527.44527.89528.34528.79529.245 425.20525.65526.10526.55527.00527.45527.90528.35528.80529.255 525.21525.66526.11526.56527.01527.46527.91528.36528.81529.265 625. 22525.67526.12526.57527.02527.47527.92528.37528.82529.275 725. 23525.68526.13526.58527.03527.48527.93528.38528.83529.285 7A25.24525.69526.14526.59527.04527.49527.94528.39528.84529.295 825. 25525.70526.15526.60527.05527.50527.95528.40528.85529.305 925. 26525.71526.16526.61527.06527.51527.96528.41528.86529.315 1025.27525.72526.17526.62527.07527.52527.97528.42528.87529.325 1125.28525.73526.18526.63527.08527.53527.98528.43528.88529.335 11A25.29525.74526.19526.64527.09527.54527.99528.44528.89529.345 1225.30525.75526.20526.65527.10527.55528.00528.45528.90529.355 1325.31525.76526.21526.66527.11527.56528.01528.46528.91529.365 1425.32525.77526.22526.67527.12527.57528.02528.47528.92529.375 1525.33525.78526.23526.68527.13527.58528.03528.48528.93529.385 15A25.34525.79526.24526.69527.14527.59528.04528.49528.94529.395 1625.35525.80526.25526.70527.15527.60528.05528.50528.95529.405 1725.36525.81526.26526.71527.16527.61528.06528.51528.96529.415 1825.37525.82526.27526.72527.17527.62528.07528.52528.97529.425 1925.38525.83526.28526.73527.18527.63528.08528.53528.98529.435 19A25.39525.84526.29526.74527.19527.64528.09528.54528.99529.445 2025.40525.85526.30526.75527.20527.65528.10528.55529.00529.455 2125.41525.86526.31526.76527.21527.66528.11528.56529.01529.465 2225.42525.87526.32526.77527.22527.67528.12528.57529.02529.475 2325.45525.90526.35526.80527.25527.70528.15528.60529.05529.505 2425.43525.88526.33526.78527.23527.68528.13528.58529.03529.485 2525.44525.89526.34526.79527.24527.69528.14528.59529.04529.495 2625.46525.91526.36526.81527.26527.71528.16528.61529.06529.515 2725.47525.92526.37526.82527.27527.72528.17528.62529.07529.525 2825.48525.93526.38526.83527.28527.73528.18528.63529.08529.535 2925.49525.94526.39526.84527.29527.74528.19528.64529.09529.545 3025.50525.95526.40526.85527.30527.75528.20528.65529.10529.555 3125.51525.96526.41526.86527.31527.76528.21528.66529.11529.565 3225.52525.97526.42526.87527.32527.77528.22528.67529.12529.575 3325.53525.98526.43526.88527.33527.78528.23528.68529.13529.585 3425.54525.99526.44526.89527.34527.79528.24528.69529.14529.595 3525.55526.00526.45526.90527.35527.80528.25528.70529.15529.605 3625.56526.01526.46526.91527.36527.81528.26528.71529.16529.615 3725.57526.02526.47526.92527.37527.82528.27528.72529.17529.625 3825.58526.03526.48526.93527.38527.83528.28528.73529.18529.635 3925.59526.04526.49526.94527.39527.84528.29528.74529.19529.645 4025.60526.05526.50526.95527.40527.85528.30528.75529.20529.655 4129.665 4229.675 4329.685 4429.695