Amateur radio station since 1993
RA3WDK `s Homepage



I like old vintage receivers. You can see photo my old USSR VEF-202 radio receiver.


Manufactured in Riga, Latvia, VEF

(my receiver was made on 1979)

Super-Heterodyne receiver

( only 10 semiconductor transistors) have LW and some SW broadcast band.

I added 19m and 17m bands.

(easy for this receivers, you need only free band-plate for make new band).

I have made also CW local oscillator (LO) in IF frequency 465 kHz. This LO mast be set near IF amplifier and receiver modification to enable them as CW/SSB-reception.

These are the VEF-202 IF filter modifications with ceramic filter 465 kHz.

The VEF-202 uses the simple LC filter 465 kHz with bandwitdh about 13-14 kHz and not good selectivity perfomance. You can install low cost ceramic IF Filter PF1P-õõ with bandwitdh 6-8 kHz. (also FP1P-õõ)

After you installed ceramic filter - you mast adjustment L32 L33 L34

and may be L36 for better bandwidth and min loss in passband !

You can see and listen my receiver after modification, i did not save voice from BC station, ....but saved CW and SSB in RadioHam`s 17 and 40 m bands:

Air 40m band

Air 17m band

Windows Media Video - WMV file

17 m SSB

17 m CW

40 m SSB

You can ask me about circuit diagram and all modification of VEF-202.

Some time ago I received confirmation of SWL from World Harvest Radio reception by means of this old receiver

Repair and clean old receiver (since 1953) RIGA-6

tube radio receiver Riga-6 has produced the "RIGAS RADIO RUPNICA"

- LW - 723-2000 m,
- MW - 187.5-576.9 m,
- SW-I - 40.5-75.9 m,
- SW-II - 24.7–32 m,
Intermediate frequency - 464 kHz
Output rated power - 1.5 watts.
Electricity supply voltage - 127 or 220 V 55 W



Repair Loudspeaker

Impedance 3,6 Ohm



I got for repair excellent receiver RIGA-104

LW: 150 - 415 kHz (2000 - 723 ì)
SW: 520 - 1600 kHz (577 - 187.5 ì)
HF1: 3.95 - 4.85 MHz (75.9 - 61.9 ì)
HF2: 4.85 - 5.9 MHz (61.9 - 50.8 ì)
HF3: 5.9 - 6.2 MHz (50.8 - 48.4)
HF4: 7.1 - 7.35 MHz (42.2 - 40.8 ì)
HF5: 9.5 - 9.8 MHz (31.6 - 30.6 ì)
HF6: 11.7 - 12.1 MHz (25.6 - 24.8 ì)
VHF: 65.8 - 73.0 MHz
(IF ÀÌ = 465 kHz, IF VHF =10.7 MHz)

Riga-104 have better sensivity than VEF-202

Good audio ! But worse bandselector and problems repairable.

Repairing old potentiometers

 The change of original components when restoring old radio or transceiver sets is always an unpleasant. In the case of potentiometers it is difficult to find double original potentiometers for RF/AF or Mic/RF PWR.

 If you hear rustling in old potentiometers of your old transceivers you need repair them with oil. My practice is to use syringe with solid oil + spirit. Usually I use russian solid oil ÖÈÀÒÈÌ-203 (ÃÎÑÒ8773-73) . You can use SIMNIA 0, PETROLEUM JELLY S68OO,Mobiltemp SHC 100, AEROSHELL 15A or good quality machine oil.

 You don`t must to open potentiometers, you must only press out some oil with spirit into potentiometers. You must to turn the potentiometer minimum 20 times from end to end. The solid oil hits to center contact and will protect contact near axis.
 This technique is very effective and, usually, these potentiometers will still perfectly efficient. But i know what in 5% of cases where the resistive surface has been damaged and way with repair potentiometer by oil does`t work.

If you need new anti log and log potentiometer- let see figure below and change your old part to new 500k Ohm...1M Ohm potentiometer and adding resistor R2.

Getting from : Electronic Instruments, MIT Radiation Lab Series, Vol. 21


The Short Wave Broadcasting Bands

Short Wave Shedule

120 metres 2300-2495 kHz - For Tropical areas.
90 metres 3200-3400 kHz - For Tropical areas and Pirates stations
75 metres 3900-4000 kHz - For Europe, Africa and the Middle East.
60 metres 4750-4995 kHz - For Tropical areas
48 metres 5900-6200 kHz -High activity BC band and Pirates stations
41 metres 7200-7450 kHz - High activity BC band
31 metres 9400-9900 kHz - High activity BC band
25 metres 11600-12100 kHz - High activity BC band

22 metres 13570-13870 kHz - High activity BC band
19 metres 15100-15800 kHz - High activity BC band
16 metres 17480-17900 kHz - High activity BC band

15 metres 18900-19020 kHz
13 metres 21450-21850 kHz -High activity BC band
11 metres 25670-26100 kHz