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Also test the radio without the earth connection, only using the antenna A1. With a exact adjustment
of the feedback, the sensitivity is sufficient to pick up powerful stations. On the other hand, a longer
antenna with an earth connection can overload the receiver. In which case, use the looser antenna
coupling on the connection A2 or A3.
The LED serves to indicate that the radio is on and shows the state of the battery. Flickering at high
volume indicates a weak battery. The voltage collapses and reduces the LED current due to the
increased current consumption of the loudspeaker amplifier.
Reception in Practice
When tuning the frequency you will find some short-wave bands with multiple channels. It is possible
to obtain a long range on shortwave by day, but many stations however are not turned in until the
evening. The 75-m band is below 4 MHz and this band is missing on many shortwave radios. Using
this, you can listen to several interesting stations in the evening. The 49-m band at 6 MHz is densely
occupied by many European stations. Some frequencies are successively used by different stations.
The 41-m band above 7 MHz is increasingly used only in the evening. The receiver also receives parts
of the 31-m band above 9 MHz.
In general, there is a longer range at higher frequencies. Sometimes, it is also possible to receive non-
European stations. There are numerous radio stations between the broadcast bands: in CW (Morse
telegraph), SSB (single sideband radio), RTTY (radio-teletypes) and Weather fax (facsimile transmis-
sion). All these stations can be received only with the feedback turned up.
The best adjustment of the feedback controller requires some skill and plenty of practice. When fast
tuning through the various radio bands, you can initially tune, with the feedback turned up, whereby
most channels give loud whistling noises. Then turn the feedback as far back as required so you can
listen clearly to the individual stations. With the best feedback adjustment and when the antenna cou-
pling is not too strong, the Audion is very selective and has a small reception bandwidth of less than
10 kHZ. Thus, the variable capacitor must be adjusted very carefully. For powerful stations, the feed-
back regulates back a bit itself; the bandwidth increases thereby.
Test the receiver with different antenna sockets, and various antenna lengths as well as with and
without an earth connection. A long antenna can be used with the minimum coupling, when connect-
ed to A3. You can recognise when the antenna coupling is too strong, as the stations are definitely
loud, but can no longer be clearly separated.
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Travaux de soudage
Pour le montage de la radios il faut 13 câbles. Couper des tronçons de fil des longueurs suivantes :
3 x 2 cm / 1 x 6 cm / 1 x 7 cm / 5 x 8 cm / 1 x 9 cm / 1 x 10 cm / 1 x 12 cm
Enlever l'isolation à l'extrémité sur une longueur de 5 mm. L'isolation de plastique est relativement
molle et peut être retirée avec un peu de force au moyen des ongles. Torsader les conducteurs iso-
lés à l'aide des doigts. Étamer soigneusement les extrémités de câble dénudées afin que les
conducteurs ne s'ouvrent pas. Pour cela, tenir la pointe du fer à souder simultanément avec le métal
d'apport sur les extrémités de câble. L'étain de soudage doit totalement entourer le fil.
Si vous n'avez pas encore beaucoup d'expérience avec le soudage, l'étamage des extrémités de
câble est un excellent exercice qui ne peut que réussir.
Ensuite souder la platine. Pour plus de détails, voir le schéma de câblage du récepteur sur la derniè-
re page du manuel.
Composants sur la platin
Équipez la platine des composants électronique selon le schéma d'équipement. Commencer par les
résistances R1, 1 kΩ (marron, noir, rouge), R2, 10 kΩ (marron, noir, orange), R3, 4,7 kΩ (jaune, vio-
let, rouge) et R4, 470 kΩ (jaune,violet, jaune). Toutes les résistances sont montées debout. Replier
les fils de raccordement et les introduire dans les orifices correspondants de la platine.
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