DEGEN DE1103 User Manual download pdf

DEGEN DE1103: Correcting the errors

The original Russian version of this article can be found at

http://www.radioscanner.ru/info/radio/degen2.php

Translation by Altavista Babel Fish, Edited by Luigi Sain, Montreal, Canada

The idea of writing this article came to me soon after the first review was

published, with the several following months bringing forward the corrections which

were required. During that time many visitors of the http://www.radioscanner.ru website

bought the receiver, and stormy discussions ensued on the pages of our forum. In

addition, I received many letters from DE1103 users with their comments and

evaluations.

In spite of the many positive qualities of the DEGEN DE1103, some improvements can

be made to make it work even better. This conviction accompanied me from the first days

of using the receiver. Moreover with the passing of time, the benefits and drawbacks of

the receiver seen in the first survey were confirmed. The more time passed, and with

more DE1103 owners, the more complete the picture became. And here now, when all

the strong and weak points of the Chinese receiver are known by almost everyone, I

decided to actually realize the considerations and wishes of forum members.

The purpose of this article – is to sum up our desired improvements and to actually

perform them on an actual DE1103. After repeating these simple recommendations, you

will obtain an entirely different receiver. It will look the same from the outside, but it will

be free of its "infancy problems", and it will work better and be more convenient to use.

When devising the improvements to the DE1103, I strived to make the

improvements as simple as possible, using repetitive steps. This article provides concrete

details of the modifications performed. To modifications will require simple tools and

several inexpensive materials. However all my recommendations require to "surgically"

operate in the receiver. Therefore for those, who are not very familiar with the technology

and who do not feel confident in performing the steps given below, I advise you to refrain

from doing this independent work, and to entrust this matter to an experienced specialist.

I consider it necessary to warn that the author does not bear responsibility for the risk of

possibly damaging the receiver by performing any of the modifications published below.

It did not take long to come up with the title of the article.

DEGEN DE1103. Correcting the Errors.

The main disadvantages DE1103 were noted in the first article, and are summarized as

follows:

1 2 ... 28

Summary of Contents

Page 1

DEGEN DE1103: Correcting the errorsThe original Russian version of this article can be found athttp://www.radioscanner.ru/info/radio/degen2.phpTransla

Page 2

3. Remove resistor R514 from the circuit (to the left and below the terminal labelled“VOL”).4. With a 90mm long conductor, connect the FINE lower regu

Page 3

Now you can control the volume using a more customary method of simply adjusting theFINE knob, and the fine adjustment of the third heterodyne in SSB

Page 4

automatically in SSB mode was possible, but there was a possibility to lose thepreliminary fine tuning by accidentally turning the FINE tuning wheel b

Page 5

Shielding (recommended)The shielding of the reverse side of signal PCB is extremely desirable to improve theoperation of the DE1103. This recommendati

Page 6

Two shielding methods are tested on the DE1103. The first (partial) – which was detailedin my first review, and a second method which was devised repe

Page 7

3. Clean and tin the shield attachment points on the PCB.4. Install the shields to the PCB close to the installation and solder them, as shown inphoto

Page 8

Unfortunately, automatic turnoff is not provided when the batteries are fully charged. It issaid that this feature will be provided in future models o

Page 9

After the modification it is desirable to measure the charging current used to calculate thenew battery charging time.The DE1103 charging method remai

Page 10

convenient for future selection. Attention: to choose the stored frequency (to be tuned toit) you only need to choose the tuning knob.To extend the tu

Page 11

store several "round" frequencies into the receiver memory (for example B0000 ","B1000 "," B2000 "...) for convenie

Page 12

- The inconvenient volume control- Noisiness and the instability of PLL circuit, tuning susceptibility- The constant frequency reconstruction pitch- T

Page 13

-DEGEN DE1103 Factory serial number AI017885 - new version,- DEGEN DE1103 factory serial number AI014128 - old version,- Two additional DE1103 receive

Page 14

25.000 1,8 1,1 1,026.000 1,8 1,1 1,027.000 2,0 1,1 1,028.000 2,2 1,2 1,029.000 2,8 1,6 1,229.999 3,1 2,3 1,2SSB reception response is better than the

Page 15

Freq., МHzDE1103-RS(RadioScanner)31 1,432 1,633 1,834 1,835 1,836 1,237 1,0In my receiver version the highest tuning frequency was 37.100 MHz. The syn

Page 16

The DE1103 Attenuator only works in the LW/MW/SW bands. According to themeasurement results, the attenuator vnosimoye lowers them by 14... 17 dB depen

Page 17

The analysis of results obtained in the tables allows us to select the best filter setting onthe DE1103. On the crowded VHF broadcasting bands, where

Page 18

87,4 (66,0) 7096,4 (75,0) 60101,4 (80,0) 48108,0 (86,6) 45As can be seen from the table, weakening the mirror channel in the range of "Soviet&quo

Page 19

After this, include receiver is possible will be only with accumulator voltage of higherthan 4,2 v.Other InformationHere answers to some questions fro

Page 20

tuning in SSB mode, the accuracy of the installation of heterodyne, additional AGC onthe long and medium-frequency tuning ranges.To a question about t

Page 21

The first review of the DEGEN 1103 Receiver can be found here:In English: http://www.radioscanner.ru/receivers/review/degen1103_eng.htmlOriginal Russi

Page 22

of, and that this was not done by design. This suspicion has been recently confirmed by achange they have made on the new version. A forum associate o

Page 23

The first practical part of the article is aimed at those who will open their receiver for thefirst time. It details the procedure to open the DE1103.

Page 24

Now the two housing halves are connected only by the wire tothe speaker. Unsolder the wire from the speaker contacts.For now, you can put the front ha

Page 25

Altering the antenna jack (recommended - only for the new version)You will need two through-hole mount miniature ceramic capacitors 33... 150 nF (0,03

Page 26

2. Clean the small section of the circuit trace, which leads under the cover of the secondheterodyne shield (see photo) and solder the 15nF capacitor

Page 27

1. Cut the printed circuit trace at the location shown on the photo. Clean and tin the PCBtraces as shown on the photo.2. Replace inductor L105 by the

Page 28

Compare theinitial filtercharacteristic...and after themodification:The instrument divisions are 10 MHz along horizontal and 10 dB on the vertical