446
Item nr.


Leader LSG-10 Signal Generator

Small service instrument


Data for Leader LSG-10
ProductionJapan, 1960.
Bands120kHz - 260MHz in 6 bands.
Tubes6BH7 (LF osc or amp), 12BH7A (RF osc and buffer).
Semi-
conductors
diode rectifier.
CabinetSteel. Size 25x16x12cm. Weight 2.3kg.
Power230V (12W).
Documentssite.

The Design

This small service instrument allows the alignment and checking of consumer radio's. Unlike my other generator, this one has a pilot light. According to the manual and my own observations, the accuracy of such an instrument is about 1 to 2 percent in frequency; so the dial pointer value and actual frequency may be a hundredth to a fiftieth from each other.

Such an instrument need not be terribly complicated and it contains just two tubes and a handful of other components, as you can see from these two inside pictures.


Obtained9/2016 from NVHR Market.
Condition8.
Value (est.)15€.

This Object

The power chord had some dangerous damaged spots in the isolation, fortunately I saw them before I touched them (we have 230V of mains power here!). The unit contains about 6 paper capacitors, which measured 150% of their nominal value and up, so I replaced them.

AF input and output and RF output is by banana plugs so it is easy to produce all kinds of leads. The RF signal can be modulated from an external sourse, but as tube sets have high impedances, it needs quite some voltage to get enough modulation. With an MP3 player connected, you'll hardly hear the sound in your radio.

Two modifications allow me to work more precisely with this LSG-10 than is possible with most. I installed a digital frequency readout, an eight digit unit that measures with a resolution of 10Hz. This is a great improvement over the standard precision of one to several kiloHertz. The display is invisible from the outside when the set is switched off, because it is placed behind the paper dial. Only when switched on, the digits light up and shine through the dial. They are a little bit hard to read and very hard to pfotograph. To also control the frequency more precisely, I added a small trimming capacitance to the tuning tank. The smal capacitor allows to "zero beat" Radio Paradise, after which the frequency can be read from the display.


Part of Gerard's Radio Corner.
Generated by SiteBuilder on 26/2/2024 by Gerard (g.tel@uu.nl)