326
Item nr.


VEF Spidola 232 Portable

Wave switch carousel.


Data for VEF Spidola 232
ProductionUSSR, 1983.
Price was 120 Rb.
BandsDV (800-2000m), SV1 (305-540m), SV2 (180-310m), 25 (24-26m), 31 (30-32m), 41 (40-43m), 49 (48-51m) 52 (53-78m).
Semi-
conductors
5x GT322B (HF, osc, mix, IF, IF), MP37 (gain control), D20 (AGC HF), D?? (det.), 4xMP41 (AF, AF, drivers), 2x GT402E (output); Indicator: KT3107D, 4x KT315, 4xLED.
CabinetPlastic. Size 32x21x11 cm. Weight 2.8 kg.
Power9V, Batt or external.
DocumentsSchema.

The Design

A line of multiband shortwave receivers started in 1962 in Riga with the first Spidola. It became the father of well-known receivers like the VEF206. The design remained more or less the same over two decades, and this is a later example of the Spidola line.

The dial has no station names (I liked the Cyrillic on my VEF202 a lot) but wave band markings in Cyrillic and wave lengths; no frequencies. Most markings on the set are in Cyrillic, but the name Spidola is in Latin script.


The radio has a funny signal indicator with four LEDs, extincting one by one when stronger signals are received.


Obtained2/2011 from Andrej Smirnov.
Condition7.
DisposedSold 5/2018.
Sound samplePLAY SOUND   NS had bought Fyra trains in Italy, but the trains did not run as long as a Spidola.

This Object

The radio was given to me by Andrej from Russia. It did not look bad, was complete (with antenna including the tip), but the sound was terribly distorted and there was a lot of noise.

I soon suspected something wrong with the AGC circuit; this turned out to be the case, but something different from what I first thought. AGC works in two different ways. Diode D1 provides the collector voltage for T1. And detector D2 controls T6, delivering the base voltage for all HF transistors. To my surprise, under strong signals the collector of T1 would have no higher voltage than its base, and I thought this was no good. Later I was told that transistors can still process HF signals under these circumstances. But I found out that the smoothing cap C30 for the AGC was interrupted. In this way, AGC works so fast that it nulls the modulation of the signal, especially for low audio frequencies. I replaced C30 (left) and transistors T1 and T3 to reduce noise.

A week later I heard nothing but silence, but this was because I soldered T6 badly and I could repair it.


Part of Gerard's Radio Corner.
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