[600MRG] 600MRG Digest, Vol 65, Issue 22

[w7aln at netzero.com]

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------ Original message------From: 600mrg-request at w7ekb.comDate: Sun, Sep 25, 2016 10:00 AMTo: 600mrg at w7ekb.com;Cc: Subject:600MRG Digest, Vol 65, Issue 22
Send 600MRG mailing list submissions to600mrg at w7ekb.comTo subscribe or unsubscribe via the World Wide Web, visithttp://w7ekb.com/mailman/listinfo/600mrg_w7ekb.comor, via email, send a message with subject or body 'help' to600mrg-request at w7ekb.comYou can reach the person managing the list at600mrg-owner at w7ekb.comWhen replying, please edit your Subject line so it is more specificthan "Re: Contents of 600MRG digest..."Today's Topics:   1. LF boat anchor receivers (Rudy Severns)   2. Re: LF boat anchor receivers (Kenneth G. Gordon)----------------------------------------------------------------------Message: 1Date: Sat, 24 Sep 2016 13:56:14 -0700From: "Rudy Severns" To: "600MRG" <600mrg at w7ekb.com>Subject: [600MRG] LF boat anchor receiversMessage-ID: <000001d216a6$16e5b220$44b11660$@net>Content-Type: text/plain;charset="us-ascii"To those LF/MF ops within driving distance to Eugene, OR. I have a collection of very old LF/MF navy receivers (WWII) some of whichactually work.  I do not need more than one sample of each but I have somemultiples which I would be happy to give to those willing to pick them up(60-80 lb each!): 1)      RBL 22)      RBL63)      RBA4)      HF mate to RBL5)      RAL 7, HF mate to RAK6)      BC3487)      RAS It's time for me to clean house and I have other stuff like large aircapacitors, RF ammeters, etc, which could be very useful for an LF/MFstation.  I would be happy to send these to a good home. Contact me off the reflector. 73, Rudy N6LF, WD2XSH/20------------------------------Message: 2Date: Sat, 24 Sep 2016 14:57:26 -0700From: "Kenneth G. Gordon" To: 600MRG at w7ekb.comSubject: Re: [600MRG] LF boat anchor receiversMessage-ID: <57E6F6C6.10705.437882B at kgordon2006.frontier.com>Content-Type: text/plain; charset=US-ASCIIOn 24 Sep 2016 at 13:56, Rudy Severns wrote:> To those LF/MF ops within driving distance to Eugene, OR.> > I have a collection of very old LF/MF navy receivers (WWII) some of which> actually work.  I do not need more than one sample of each but I have some> multiples which I would be happy to give to those willing to pick them up> (60-80 lb each!):> > 1)      RBL 2> > 2)      RBL6For those who don't know, the RBL series were VLF receivers covering 15 through 600 kHz, designed by National which have direct-frequency readout dials and good filters. They have a built-in 110 VAC supply. The circuit type is TRF with 2 RF amplifiers (6SK7s), a regenerative detector (6SK7), 2 stages of audio amplification, (6SG7, 6K6) and an audio limiter (6H6). Rectifier is a 5Y3. They are very robust receivers and work well. > 3)      RBAThis is possibly the last TRF designed by RCA and is considered the peak of the VLF TRF receiver design. It can use the same power supply as the RBB and RBC recievers. It has 3 RF amplifiers, the third of which is operated at very low plate and screen voltages (15V) so that it operates as a limiter. This last stage also has an input to it from a local heterodyne oscillator operating 1 kHz from the operating frequency and tuned with it. The output of the 3rd RF amp then feeds a triode plate detector. This is followed by a 1st audio amp, an audio limiter, and an audio output stage which is designed to feed from 1 to 20 sets of headphones.  > 4)      HF mate to RBL> > 5)      RAL 7, HF mate to RAKI consider the RAL-7, also designed by RCA, to be the finest HF TRF receiver I have ever known. It covers from 300 kHz through 23 MHz. I used one for at least 12 years as my only station receiver. It uses the older 6 pin tubes, has 2 RF amp stages, a regen detector, 2 stages of audio and an "audio AGC" which is basically a limiter. It is unusually stable, very sensitive, and very selective for a TRF. It has a very wide-ranged switchable (to frequency) audio filter system.I have photos of some of these receivers on my website at:http://www.w7ekb.com/glowbugs/BA/index.html> 6)      BC348My first GOOD station receiver. A very fine piece of equipment> 7)      RASA National "HRO" type of receiver using plug-in coils, but with an IF of 175 kHz. An excellent receiver for the lower bands. Its 175 kHz IF does not produce good image rejection on the higher bands.Manuals for all of the above arfe available from http://bama.edebris.com/manuals/ under Military.> It's time for me to clean house and I have other stuff like large air> capacitors, RF ammeters, etc, which could be very useful for an LF/MF> station.  I would be happy to send these to a good home.> > Contact me off the reflector.> > 73, Rudy N6LF, WD2XSH/20Thanks, Rudy. Ken W7EKB---This email has been checked for viruses by Avast antivirus software.https://www.avast.com/antivirus------------------------------Subject: Digest Footer_______________________________________________600MRG mailing list600MRG at w7ekb.comhttp://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com------------------------------End of 600MRG Digest, Vol 65, Issue 22**************************************