Conrad UKW User Manual

Imprint

© 2011 Franzis Verlag GmbH, 85586 Poing
www.franzis.de

Author: Burkhard Kainka
Art & Design, Composition: www.ideehoch2.de

ISBN 978-3-645-10057-1

Produced on the order of Conrad Electronic SE, Klaus-Conrad-Straße 1, D92240 Hirschau

All rights reserved, including the rights of photo-mechanical reproduction and storage in electronic media.
Generation and distribution of copies on paper, data carriers or online, in particular as PDF, is only permissi­ble with the express consent of the publisher; violation of this will be prosecuted.
Most product designations of hard- and software and company logos named in this booklet are usually also
registered trademarks and should be observed as such. The publisher essentially uses the manufacturer’s
spellings for the product designations.
All circuits and programmes introduced in this book were developed, tried and tested with the greatest possi­ble care. Nevertheless, mistakes in the book and software cannot be fully excluded. The publisher and author
do not assume any liability for incorrect information and their consequences.

Electric and electronic devices must not be disposed of in the domestic waste! At the end of its service life, dis­pose of the product according to the relevant statutory regulations. Collection points for returning electronic
devices free of charge have been established. Your municipality will inform you of where such collection
points are located.

This product complies with the relevant CE directives if used according to the included instructions. The descrip­tion belongs with the product and must be passed on with it.

2

UKW Retro Radio

The UKW Retro Radio 4

Components 5

Installation of Control Elements 6

Soldering 8

First Test and Settings 12

Reception Practice 13

Explanations on the Circuit Diagram 13

3

4

The UKW Retro Radio

This state-of-the-art VHF radio with traditional design receives FM stations in the
range of 87.5 MHz to 108 MHz with good reception performance. You will mainly
hear the strong local stations with good sound. However, the receiver is sensitive
enough to also receive remote stations at times.

VHF radio was not widely introduced before 1945. Initially, there were still many
radios that were only able to receive the AM ranges long wave, medium wave
and short wave. Many devices could be retrofit to receive VHF. The tube superhet
with VHF range became generally popular in the 1950s.

This radio looks reminiscent of a typical portable radio from the 1960s. With in­vention of the transistor, radios could be built that could be operated at lower
energy than tube receivers. They could therefore also be battery-operated. Apart
from this, they remained technically similar to older tube radios.

D1 varactor diode 1SV101
R1 4.7 kO (yellow, violet, red)
R2 220 kO (red, red, yellow)
R3 1 kO (brown, black, red)
R5 330 kO (orange, orange, yellow)
R6 33 O (orange, orange, black)
C15 Elko 100 µF
C17 100 nF ceramic (104)

5

With the highly integrated receiver IC TDA7088, construction of a dedicated VHF
radio has become so simple that anyone is able to successfully solder together
this radio. The single-ended low frequency amplifier works similar to the historic
tube radio template. Your nostalgic radio uses a two-level transistor amplifier
with medium volume at low battery voltage. Now, two 1.5 V alkaline batteries are
sufficient for up to 100 hours of radio reception. Your self-made radio will make
listening to the radio even more fun. Enjoy the diversity of the VHF stations.

Components

Pre-equipped PCB with TDA7088
rod aerial
speakers 8 O, 0.5 W
volume control 22 kO with switch
tuning control 22 kO
insulated wire
battery compartment with connection wires
T1 PNP transistor BC557B
T2 NPN transistor BC547B