LwEa und T8PL39
Lw.E.a. front view
The receiver seen from above, it looks quite "radio-amateur'ized" with most of the screen lids missed,
but in facts I got it from Bergen radio (LGN Rundemanen) and the IF rejection coil - of all things - has
been aligned so many times with bad screw drivers that the core doesn't look good, but the other cores
are not vandalized - perhaps they didn't dare!
Lw.E.a. - Langwellenempfänger 'Anton'
I 72-128kHz (wht)
II 122-241kHz (Red)
III 230-430kHz (Yel)
IV 410-800kHz (Blu)
V 760-1525kHz (Grn)
Circuit: 8?x RV2P800 as???
The RX has no AGC, and RF and Audio gain control are combined on one knob.
IF=60,9 kHz. BFO: 60kHz xtal and 61,8kHz tuned circuit.
NA6/NA6a mains power supply, EU.d converter for 12V supply
It should be mentioned that neither any of my Kw.E.a's nor Lw.E.a have needed any sort of repair,
no capacitors have been found defective in any way. But this may not indicate that they are not bad in
any ways, they just work satisfactorily. Lw.E.a sounded somewhat noisy when I tested it last year after
being inactive for many years, but the noise dissappeared after some days operation. I suppose it was
caused by bad contacts rather than leaky capacitors. Feldfernschreiber 24a-32 and Torn.Fu.d2 is different
story, while Torn.Fu.b1 seems better in such respect. I got the Lw.E.a at Bergen radio, LGN in 1976.
The following files are available, see the links below (tnx LA6TJA):
D914/1 cover (1278kB)
LwEa_Teilliste (1346kB) http://www.agder.net/la8ak/12345/images/0216_018.pdf
LwEa Schaltbild (827kB) - http://www.agder.net/la8ak/12345/images/0223_001.pdf
LwEa Vereinfachtes Schaltbild (112kB) - http://www.agder.net/la8ak/12345/images/0224_001.pdf
LwEa circuit in gif format, see page n74
Lw.E.a IF filter. It is two similar IF-stages on 60,9kHz. The circuit is drawn such that the similarities/differences with Kw.E.a can be seen.
One must consider the bias circuit when building a power supply for the receiver, similar circuit for KwEa, FuHEc, FuHEu, TornEb.
Type plates and
remarks for Kw.E.a and Lw.E.a
T8PL39. It is funny to see how much the chassis looks like Lw.E.a
The two TE30 at the far left side, then RF, Mixer, Osc, 2x IF, detector, audio and BFO at upper left side.
T8PL39 vs. Lw.E.a.
T8PL39 "Martin" (E491 N)
This is a DF receiver, in-spite of that what the front looks like, the chassis looks very
much like Lw.E.a. (and Kw.E.a)
The circuit diagram is very much like Lw.E.a, but the valves are RV12P2000.
It has a 4-section tuning capacitor. Two tuned circuits ahead of the RF amplifier.
The receiver has the following stages:
RF-amplifier, Mixer, Local Osc., 1st and 2nd IF-amplifiers, Detector and audio amp.
(diode/triode connected valve), BFO/CAL, Audio output. The detector/audio amplifier
is very much like E52, but it is no AGC detector. It is two double tuned IF
bandpassfilters for the selectivity.
BFO: 60/61,8kHz (60.9 + 0.9kHz). Suppose the pitch is intended to be 900Hz.
Valves: 8x RV12P2000
Stabilovolt STV75/15 II
Osram 3766, 6418 and 57.7130 lamps
BW Pos 1-5. emission A1A 1-5µV
BW pos.1 emission A2A 5-20µV
Selectivity (3dB bandwidth): 5 steps 300Hz...8kHz.
Band I 1kHz, Band II 1,2kHz, Band III 1,5kHz, Band IV 3kHz, Band V 3,5kHz.
|IF rejection:||Band I minimum 80dB||= 10E-6 ( @ 87kHz)|
|Image rejection:||400kHz 10E-6 (60dB)||200kHz 2*10E-6 (66dB)||120kHz 4*10E-6(72dB)|
It is two similar IF-stages on 60,9kHz, it seems to be very much the same as for Lw.E.a, and I would have to check more carefully later (miss proper docs. for LwEa).
The bandpassfilter circuit is drawn such that the similarities/differences with Kw.E.a can be seen.
T8PL39. Maße: 340 h, 668 b, Tiefe: 355mm
Data for RV12P2000
RV12P2000 and the special purpose AF100, it has a somewhat different socket (8pin) - more like RL4,8P15.
NA6a. The most commonly used power supply for Kw.Ea, Lw.Ea (and Fu.H.E.c).
A switch adds resistor to compensate for the 0.4A lower filament current of LwEa (1,8A) compared to 2,2A for KwEa
|Artikler i 'Amatör Radio' og
Brug af STV280/40....................................... OZ7AQ OZ 70-04-117
Kw.E.a. Brumfri likeretter for mottakeren....... OE3UK AR 63-04-053
Kw.E.a. Forbedringer for SSB .......................LA8AK AR 73-09-195
Kw.E.a. Kraftforsyning................................... LA4HK AR 71-07-167
Lw.E.a. Reparasjon av mottakeren.................. LA7MI AR 85-10-269
Maling av Wehrmacht og Luftwaffeutstyr......... LA8AK AR 95-02-044
RV12P2000 og RV12P2001 brukes i nyeste mottakere AR 51-09-246
Sirutor 5a og 5b dioder, erstatning .... LA4OE, LA8AK AR 95-02-044
Solidstate supply ideas for 12V operation
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