E52b Main Page
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E52b-7
| Köln E52 is the best short-wave receiver produced
under WW2. The performance can be compared with the R390. R390 is a famous US receiver from the 50’s and 60's. E52 is a super heterodyne receiver with an IF frequency on 1 MHz. The MF filter is extremely good with a variable bandwidth from 200 Hz to 10 KHz and with a flat pass band. Mirror frequency is < 1: 50000. |
LA8AK's drawing
| This is a block diagram over Köln. The HF amplifier have 5-gang tuned circuits. The oscillator capacitor tuning capacitor is synchronised with the HF amplifier capacitors in a 6-gang capacitor. This heavy filtering gives a very good rejection of unwanted signals. Both mirror frequency and large signals on frequencies near the operating frequency. The MF section is very advanced. It has 6 tuned circuits before the first amplifier. Then the signal pas a XTAL filter, amplifier and a second XTAL filter. The pass band of the XTAL filter can be selected from 200 Hz to 10 kHz with the pass band regulator. |
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Specifications for the E52 'Köln'
| Frequency ranges Modes Power requirement Dimensions Weight Sensitivity Image rejection IF rejection IF frequency BFO Bandwidth Frequency stability |
1480-3020kHz 2980-6040kHz 5975-10050kHz 9950-17700kHz 17600-25200kHz A1, A2, A3 110-230VAC 50-60Hz, or 12VDC 245mm x 446mm x 350mm 40,8kg AM (wide) 3,5µV CW (wide) 1µV CW (narrow) 0,3µV Better than 94dB @20MHz Better than 100dB 1000 kHz XTAL - 1000,9kHz or 995 kHz - 1005 kHz continuously variable between 200 HZ - 10 kHz better than 30 x 10 E-6 °C |
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E52 LINKS:
http://www.agder.net/la8ak/24a.htm
http://www.agder.net/la8ak/12a.htm
http://www.agder.net/la8ak/12b.htm
http://www.richardsradios.co.uk/g2awa.html