[Premium-Rx] Premium-Rx Digest, Vol 104, Issue 4
Martin Cook
martin_cook at ihug.co.nz
Thu Jul 16 21:21:22 EDT 2015
Good Morning Guys,
[quote}The BCB performance of the 515 has been roundly criticized by
pretty
much everyone. You need to peak the BFO/BC control as you tune the
BCB. Even peaked, there is a 15-18dB signal loss. See p. 11:
<www.radiomanual.info/schemi/RX/JRC_NRD-515_review.pdf>
[unquote]
A simple snip of the two resistors R5 and R6 in the BC band filter
network and soldering the two
wire ends together removes the 5dB attenuator. Works well for me but may
lead to cross-mod if
you live near a high power BC Transmitter. Also chop out the diodes CD83
to 86 and ensure
the attenuator relays K1 and K2 are working and clean!
There are trimmers to set the tuning range of the front end BC band
filter - mine were badly adjusted
so that you could not peak the filter above 1450kHz. It pays to make
sure that the peak occurs at or even past 1600kHz. It's quite fiddly to
get the full range.
The review also commented on the 'coarseness' of the RIT (Delta F)
control. I replaced mine with
a 10-turn potentiometer which works well too. I believe there was a mod
kit by a US company
(Drake?)that did the same thing and had a nice turns counter to replace
the knob - unobtainable
now I guess.
Kind regards - Martin ZL2MC
------ Original Message ------
From: premium-rx-request at mailman.qth.net
To: premium-rx at mailman.qth.net
Sent: 17-Jul-15 12:12:26
Subject: Premium-Rx Digest, Vol 104, Issue 4
>Send Premium-Rx mailing list submissions to
> premium-rx at mailman.qth.net
>
>To subscribe or unsubscribe via the World Wide Web, visit
> http://mailman.qth.net/mailman/listinfo/premium-rx
>or, via email, send a message with subject or body 'help' to
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>
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>
>When replying, please edit your Subject line so it is more specific
>than "Re: Contents of Premium-Rx digest..."
>
>
>Today's Topics:
>
> 1. Re: Odd behavior by NRD-515 (Charles Steinmetz)
> 2. Re: Odd behavior by NRD-515 (Cecil Acuff)
> 3. Re: Odd behavior by NRD-515 (Arthur Delibert)
> 4. Re: Premium-Rx Digest, Vol 104, Issue 3 (Dan Robinson)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Thu, 16 Jul 2015 18:43:08 -0400
>From: Charles Steinmetz <csteinmetz at yandex.com>
>To: PremiumRX <premium-rx at mailman.qth.net>
>Subject: Re: [Premium-Rx] Odd behavior by NRD-515
>Message-ID: <20150717014313.hCjG5I2Q at smtp2h.mail.yandex.net>
>Content-Type: text/plain; charset="us-ascii"; format=flowed
>
>Howard wrote:
>
>>Sure enough, I found just what he did. In tuning through the single
>>step from 599.9 kHz to 600.0 kHz, the background hiss goes from
>>normal to virtually absent, a very striking change.
>>
>>The band of decreased sensitivity corresponds so closely to the MW
>>broadcast band that I wonder whether this is a coincidence.
>
>The BCB performance of the 515 has been roundly criticized by pretty
>much everyone. You need to peak the BFO/BC control as you tune the
>BCB. Even peaked, there is a 15-18dB signal loss. See p. 11:
>
><www.radiomanual.info/schemi/RX/JRC_NRD-515_review.pdf>
>
>Best regards,
>
>Charles
>
>
>
>
>
>------------------------------
>
>Message: 2
>Date: Thu, 16 Jul 2015 18:25:39 -0500
>From: Cecil Acuff <chacuff at cableone.net>
>To: Howard Ritter <hlritter at bex.net>
>Cc: boatanchors at mailman.qth.net, "Premium-Rx at mailman.qth.net"
> <premium-rx at mailman.qth.net>
>Subject: Re: [Premium-Rx] Odd behavior by NRD-515
>Message-ID:
> <CAHt76NtRUuToTbzsOgEbF7iyok8rKyrOq1c2NNdCR7Gq3MMoMw at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>Greetings,
>
>Two things to know about this receiver... It has a built I attenuator
>for
>the BC band that is switched in below 1600khz...
>
>Also when you switch I to the range of the BC band you have a
>preselected
>to tune to peak up the sensitivity. I forget which knob it's on but
>it's
>marked on the front panel. If you or your buyer didn't know of that a
>greatly reduced level of sensitivity will be experienced. It's also
>possible the preselected has a problem and is not peaking properly
>resulting I abnormally low sensitivity.
>
>The preselected only comes into play on the BC band so if you never
>used it
>there you might not have k own about it.
>
>Check that and see if it doesn't help the problem a bit....
>
>Cecil
>On Jul 16, 2015 5:14 PM, "Howard Ritter" <hlritter at bex.net> wrote:
>
>> Sorry for the semi-off topic post (somewhere between a Premium RX and
>>a
>> boat anchor!), but where else can you get this level of expertise?
>>
>> I have just had the embarrassing and expensive experience of having
>>an
>> eBay seller return the Japan Radio Co NRD-515 receiver he?d bought
>>from me,
>> after finding severely reduced sensitivity between 600 and 1600 kHz.
>>I?d
>> never used it for BCB listening, so this problem had escaped me.
>>
>> Briefly, this is a synthesized solid-state GC receiver that tunes a
>>lot
>> like the Collins 51-S1, with one knob to select one of 30 1-MHz
>>ranges and
>> another knob to tune through the 1-MHz range that?s selected. It?s
>> possible, with continuous turning of the tuning knob, to move through
>>the
>> ends of any 1-MHz range and into the next. Freq is digitally
>>displayed to
>> 0.1 kHz. I simplistically envision the process as that of
>>synthesizing a
>> base frequency as specified by the MHz knob and mixing that with a
>>variable
>> freq determined by the tuning knob. That?s why I couldn?t picture why
>>a
>> decrease in sensitivity would affect just part of just a single 1-MHz
>>band.
>> I was skeptical until I got the receiver back and put it on the air.
>>
>> Sure enough, I found just what he did. In tuning through the single
>>step
>> from 599.9 kHz to 600.0 kHz, the background hiss goes from normal to
>> virtually absent, a very striking change. Very few stations are
>>received,
>> weakly, up to around 1100, above which there is still abnormally
>>little
>> atmospheric hiss but a few (strong?) stations are heard. Continuing
>>to tune
>> upward, background noise reappears but remains low up through 1599.9
>>kHz,
>> after which it abruptly returns to normal at 1600.0. It?s probably
>> significant that this change in frequency is accompanied by the sound
>>of
>> what I take to be a relay clicking inside the radio, although there
>>is no
>> such sound at 600, or anywhere else in continuously tuning except for
>> 4999.9?5000.0 (although when I switch ranges with the MHz knob, the
>>relay
>> clicks at 2, 3, and 4 MHz). I have tuned the entire spectrum with
>>both the
>> dial and the UP?DOWN switch and have found no other place where the
>> sensitivity drops out like it does from 600 to 1599.9. The decrease
>>in, and
>> return of, hiss occur whether I tune into the 0?1 MHz and 1?2 MHz
>>bands
>> with the MHz range knob or by twirling the tuning dial, and whether I
>> approach from above or below.
>>
>> The band of decreased sensitivity corresponds so closely to the MW
>> broadcast band that I wonder whether this is a coincidence. It would
>>make
>> sense if the receiver were to automatically switch to a different
>>antenna
>> input when it?s tuned to the BCB, and that could explain the sound of
>>the
>> relay?except that there?s no separate antenna input for a BCB or
>>ferrite
>> antenna. It may be significant that, outside the affected frequency
>>range,
>> the background hiss drops markedly when the antenna lead is
>>disconnected?in
>> fact, to the same level as the background hiss within the affected
>>range.
>> And, within the affected range, the hiss does NOT drop when the
>>antenna is
>> taken off. This suggests to me that the RF from the antenna is not
>>getting
>> amplified within that range. Still, why or how a problem could affect
>>just
>> part of one tuning band and the adjacent part of another band,
>>spanning
>> exactly 1000.0 kHz, remains a mystery.
>>
>> Any ideas?
>>
>> Thanks,
>> ?howard n7exn
>>
>> ______________________________________________________________
>> Premium-Rx mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>> Help Page: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Premium-Rx at mailman.qth.net
>> Help Contact eMail: paul at 8zo.com
>> Home Page: http://www.premium-rx.org/
>>
>
>
>------------------------------
>
>Message: 3
>Date: Thu, 16 Jul 2015 19:37:47 -0400
>From: Arthur Delibert <radio75a3 at msn.com>
>To: Howard Ritter <hlritter at bex.net>, Premium Receiver Group
> <premium-rx at mailman.qth.net>, "boatanchors at mailman.qth.net"
> <boatanchors at mailman.qth.net>
>Subject: Re: [Premium-Rx] Odd behavior by NRD-515
>Message-ID: <BLU177-W26A46B93FD446B0B81D41E4990 at phx.gbl>
>Content-Type: text/plain; charset="Windows-1252"
>
>Your story made me run to the shelf and get out my NRD-515. Tuning
>first to a station on 600 kHz, and peaking the BC Tune control for that
>frequency, I find that the station drops from S-9 to about 7.5 as I
>tune from 599.9 to 600. Tuning to 1599.9, where we have a local
>station, and re-peaking the BC Tune control, the station drops from
>about 30 over S9 to about 23 over as I tune from 1599.9 to 1600.
>
>So it could be that your buyer (1) was neglecting to peak the BC Tune
>control, and/or (2) didn't know the 515 has reduced sensitivity in the
>BCB. Try the same procedure I did and see if you get similar results.
>If so, I think you're receiver is fine.
>
>Art
>KB3FJO
>
>> From: hlritter at bex.net
>> Date: Thu, 16 Jul 2015 18:14:00 -0400
>> To: Premium-Rx at mailman.qth.net; boatanchors at mailman.qth.net
>> Subject: [Premium-Rx] Odd behavior by NRD-515
>>
>> Sorry for the semi-off topic post (somewhere between a Premium RX and
>>a boat anchor!), but where else can you get this level of expertise?
>>
>> I have just had the embarrassing and expensive experience of having
>>an eBay seller return the Japan Radio Co NRD-515 receiver he?d bought
>>from me, after finding severely reduced sensitivity between 600 and
>>1600 kHz. I?d never used it for BCB listening, so this problem had
>>escaped me.
>>
>> Briefly, this is a synthesized solid-state GC receiver that tunes a
>>lot like the Collins 51-S1, with one knob to select one of 30 1-MHz
>>ranges and another knob to tune through the 1-MHz range that?s
>>selected. It?s possible, with continuous turning of the tuning knob,
>>to move through the ends of any 1-MHz range and into the next. Freq is
>>digitally displayed to 0.1 kHz. I simplistically envision the process
>>as that of synthesizing a base frequency as specified by the MHz knob
>>and mixing that with a variable freq determined by the tuning knob.
>>That?s why I couldn?t picture why a decrease in sensitivity would
>>affect just part of just a single 1-MHz band. I was skeptical until I
>>got the receiver back and put it on the air.
>>
>> Sure enough, I found just what he did. In tuning through the single
>>step from 599.9 kHz to 600.0 kHz, the background hiss goes from normal
>>to virtually absent, a very striking change. Very few stations are
>>received, weakly, up to around 1100, above which there is still
>>abnormally little atmospheric hiss but a few (strong?) stations are
>>heard. Continuing to tune upward, background noise reappears but
>>remains low up through 1599.9 kHz, after which it abruptly returns to
>>normal at 1600.0. It?s probably significant that this change in
>>frequency is accompanied by the sound of what I take to be a relay
>>clicking inside the radio, although there is no such sound at 600, or
>>anywhere else in continuously tuning except for 4999.9?5000.0
>>(although when I switch ranges with the MHz knob, the relay clicks at
>>2, 3, and 4 MHz). I have tuned the entire spectrum with both the dial
>>and the UP?DOWN switch and have found no other place where the
>>sensitivity drops out like it does from 600 to 15
> 99.9. The decrease in, and return of, hiss occur whether I tune into
>the 0?1 MHz and 1?2 MHz bands with the MHz range knob or by twirling
>the tuning dial, and whether I approach from above or below.
>>
>> The band of decreased sensitivity corresponds so closely to the MW
>>broadcast band that I wonder whether this is a coincidence. It would
>>make sense if the receiver were to automatically switch to a different
>>antenna input when it?s tuned to the BCB, and that could explain the
>>sound of the relay?except that there?s no separate antenna input for a
>>BCB or ferrite antenna. It may be significant that, outside the
>>affected frequency range, the background hiss drops markedly when the
>>antenna lead is disconnected?in fact, to the same level as the
>>background hiss within the affected range. And, within the affected
>>range, the hiss does NOT drop when the antenna is taken off. This
>>suggests to me that the RF from the antenna is not getting amplified
>>within that range. Still, why or how a problem could affect just part
>>of one tuning band and the adjacent part of another band, spanning
>>exactly 1000.0 kHz, remains a mystery.
>>
>> Any ideas?
>>
>> Thanks,
>> ?howard n7exn
>>
>> ______________________________________________________________
>> Premium-Rx mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>> Help Page: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Premium-Rx at mailman.qth.net
>> Help Contact eMail: paul at 8zo.com
>> Home Page: http://www.premium-rx.org/
>
>
>------------------------------
>
>Message: 4
>Date: Thu, 16 Jul 2015 20:12:06 -0400
>From: Dan Robinson <dxace1 at gmail.com>
>To: PREMIUM-RX <premium-rx at mailman.qth.net>
>Subject: Re: [Premium-Rx] Premium-Rx Digest, Vol 104, Issue 3
>Message-ID: <dae26ed0-3544-4a4d-b25f-3f112ddc84e7 at typeapp.com>
>Content-Type: text/plain; charset=UTF-8
>
>Re NRD 515 I would recommend Bob Sherwood who has years if experience
>modifying the receiver.? Also, Craig at KIWA...
>
>Sent from TypeMail
>
>
>
>On Jul 16, 2015, 6:14 PM, at 6:14 PM,
>premium-rx-request at mailman.qth.net wrote:
>>Send Premium-Rx mailing list submissions to
>> premium-rx at mailman.qth.net
>>
>>To subscribe or unsubscribe via the World Wide Web, visit
>> http://mailman.qth.net/mailman/listinfo/premium-rx
>>or, via email, send a message with subject or body 'help' to
>> premium-rx-request at mailman.qth.net
>>
>>You can reach the person managing the list at
>> premium-rx-owner at mailman.qth.net
>>
>>When replying, please edit your Subject line so it is more specific
>>than "Re: Contents of Premium-Rx digest..."
>>
>>
>>Today's Topics:
>>
>> 1. Re: WJ 8888-2 synthesizer failure (Francesco Ledda)
>> 2. Fwd: WJ 8888 noise floor problem (Peter Rovardi)
>> 3. Watkins Johnson 8617B- S1 CPU FS (S. Schappert)
>> 4. WJ565 Plugins. (David Schofield)
>> 5. Odd behavior by NRD-515 (Howard Ritter)
>>
>>
>>----------------------------------------------------------------------
>>
>>Message: 1
>>Date: Sat, 4 Jul 2015 07:28:30 -0500
>>From: "Francesco Ledda" <frledda at att.net>
>>To: "'R T'" <14971now at gmail.com>, "'Heinz Breuer'"
>> <hbreuer at debitel.net>
>>Cc: premium-rx at mailman.qth.net
>>Subject: Re: [Premium-Rx] WJ 8888-2 synthesizer failure
>>Message-ID: <000001d0b654$f06121f0$d12365d0$@net>
>>Content-Type: text/plain; charset="us-ascii"
>>
>>Look on Ebay; you will find the divider you need.
>>
>>Frank
>>KF5RXV
>>
>>-----Original Message-----
>>From: Premium-Rx [mailto:premium-rx-bounces at mailman.qth.net] On Behalf
>>Of R
>>T
>>Sent: Saturday, July 04, 2015 1:52 AM
>>To: Heinz Breuer
>>Cc: premium-rx at mailman.qth.net
>>Subject: Re: [Premium-Rx] WJ 8888-2 synthesizer failure
>>
>>Hello Heinz.
>>
>>I have a quad 8 which has a similar fault, which I have not been able
>>to
>>repair for some time.
>>My 8888 synthesiser uses a rare divider chip (modulo 2 division). I
>>have not
>>been able to find a replacement for it anywhere.
>>To get the radio going again I was thinking of making up a small
>>sub-board
>>using a PIC to carry out the same maths function. It's a lot of work,
>>and
>>has taken a back-seat to other projects.
>>It would be interesting to know if your 8888 has the same/similar
>>issue.
>>
>>Richard
>> Hello Glenn,
>>thanks for your message.
>>I will check the battery first thing in the morning.
>>I downloaded the manual and it seems that the battery is on A22 board
>>behind
>>the front panel.
>>Do you know of a suitable replacement for the battery?
>>vy 73 Heinz DH2FA, KM5VT
>>
>>Von meinem iPhone gesendet
>>
>>> Am 04.07.2015 um 00:26 schrieb Glenn Little WB4UIV <
>>glennmaillist at bellsouth.net>:
>>>
>>> Has the NiCad battery leaked?
>>>
>>> A leaking battery has all but destroyed two 8888B receivers here.
>>>
>>> 73
>>> Glenn
>>> WB4UIV
>>>
>>> At 04:38 PM 7/3/2015, Heinz Breuer wrote:
>>>> Hello,
>>>> I bought a Watkins-Johnson WJ 8888-2 receiver last weekend at the
>>HAMRADIO fair in Friedrichshafen/Germany at Lake Constance. The seller
>>assured me that the receiver was working fine and I have no reason to
>>doubt
>>it. Anyhow I put it up today and there is a faulty synthesizer.
>>>>
>>>> I listend to a cw station at 7,021.80 with the 500 Hz filter. When
>>>>I
>>slowly turned the vfo knop upwards the cw pitch changed as expected.
>>When I
>>reached 7,022.00 there was no change up to 7,029.99. Obviously the
>>actual
>>receive frequency did not change between 7,022.00 and 7.029.99
>>>> I noticed the same with an SSB station at 7,191.80. The receive
>>frequency didn't change between 7,192.00 and 7,199.99
>>>> Receiving condition were very poor today and I didn't have much
>>>>time
>>
>>>> to
>>evaluate the fault any further but it seems that this fault exists
>>every
>>10kHz at all freuencies xx,xx2.00 to xx,xx9.99
>>>>
>>>> As a first step I pulled every pc board one by one and put it back
>>in
>>but it didn't help.
>>>>
>>>> I have not yet downloaded the manual and schematics. This will be
>>the
>>next step. I am well aware that the receiver is almost 40 years old. I
>>know
>>that it has tantalum capacitors which are prone to failure.
>>>>
>>>> If anybody experienced a similar fault I would appreciate any hint
>>>> where
>>I should start looking.
>>>>
>>>> Thanks in advance for any help.
>>>>
>>>> vy 73 Heinz DH2FA, KM5VT
>>>> ______________________________________________________________
>>>> Premium-Rx mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>>>> Help Page: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:Premium-Rx at mailman.qth.net Help Contact eMail:
>>>> paul at 8zo.com Home Page: http://www.premium-rx.org/
>>>
>>>
>>---------------------------------------------------------------------------
>>> Glenn Little ARRL Technical Specialist QCWA LM
>>28417
>>> Amateur Callsign: WB4UIV wb4uiv at arrl.net AMSAT LM 2178
>>> QTH: Goose Creek, SC USA (EM92xx) SBE ARRL
>>TAPR
>>> "It is not the class of license that the Amateur holds but the class
>>> of the Amateur that holds the license"
>>>
>>---------------------------------------------------------------------------
>>> ______________________________________________________________
>>> Premium-Rx mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>>> Help Page: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Premium-Rx at mailman.qth.net
>>> Help Contact eMail: paul at 8zo.com
>>> Home Page: http://www.premium-rx.org/
>>>
>>______________________________________________________________
>>Premium-Rx mailing list
>>Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>>Help Page: http://mailman.qth.net/mmfaq.htm
>>Post: mailto:Premium-Rx at mailman.qth.net
>>Help Contact eMail: paul at 8zo.com
>>Home Page: http://www.premium-rx.org/
>>______________________________________________________________
>>Premium-Rx mailing list
>>Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>>Help Page: http://mailman.qth.net/mmfaq.htm
>>Post: mailto:Premium-Rx at mailman.qth.net
>>Help Contact eMail: paul at 8zo.com
>>Home Page: http://www.premium-rx.org/
>>
>>
>>---
>>This email has been checked for viruses by Avast antivirus software.
>>https://www.avast.com/antivirus
>>
>>
>>
>>------------------------------
>>
>>Message: 2
>>Date: Wed, 8 Jul 2015 16:15:42 +0100
>>From: Peter Rovardi <peter.rovardi at btinternet.com>
>>To: premium-rx at mailman.qth.net
>>Subject: [Premium-Rx] Fwd: WJ 8888 noise floor problem
>>Message-ID: <238F044B-170A-4670-A8EA-866D582924B7 at btinternet.com>
>>Content-Type: text/plain; charset=us-ascii
>>
>>
>>
>>Sent from my iPhone
>>
>>Begin forwarded message:
>>
>>> From: Peter Rovardi <peter.rovardi at btinternet.com>
>>> Date: 8 July 2015 15:52:10 BST
>>> To: premium-rx at mailman.qth
>>> Subject: Re: [Premium-Rx] WJ 8888 noise floor problem
>>>
>>> Hello,
>>> My 8888A was working fine for the last 18 yrs ( new battery fitted 5
>>yrs ago) until the 1st LO developed a fault recently. This I managed
>>to
>>cure after many hours however it has now developed another fault!
>>> This is best explained as a gradual increase in noise floor over a
>>period of some 20 to 30 minutes, from cold switch on, resulting in
>>total masking of received signals!
>>> I have used lots of "freeze it" component cooler trying to locate
>>this weird fault but to no avail.
>>> Wonder if any other 8888 fan in the group could possibily advise on
>>this problem?
>>> Not sure what WJ quoted as the MTBF for the 8888 was, but bet it was
>>a lot less than 40 yrs!
>>> Thanks &
>>> 73 to all,
>>>
>>> Peter Rovardi. G4HSB.
>>>
>>>
>>>
>>> Sent from my iPhone
>>>
>>>> On 4 Jul 2015, at 03:53, Heinz Breuer <hbreuer at debitel.net> wrote:
>>>>
>>>> Hello Glenn,
>>>> thanks for your message.
>>>> I will check the battery first thing in the morning.
>>>> I downloaded the manual and it seems that the battery is on A22
>>board behind the front panel.
>>>> Do you know of a suitable replacement for the battery?
>>>> vy 73 Heinz DH2FA, KM5VT
>>>>
>>>> Von meinem iPhone gesendet
>>>>
>>>>> Am 04.07.2015 um 00:26 schrieb Glenn Little WB4UIV
>><glennmaillist at bellsouth.net>:
>>>>>
>>>>> Has the NiCad battery leaked?
>>>>>
>>>>> A leaking battery has all but destroyed two 8888B receivers here.
>>>>>
>>>>> 73
>>>>> Glenn
>>>>> WB4UIV
>>>>>
>>>>> At 04:38 PM 7/3/2015, Heinz Breuer wrote:
>>>>>> Hello,
>>>>>> I bought a Watkins-Johnson WJ 8888-2 receiver last weekend at the
>>HAMRADIO fair in Friedrichshafen/Germany at Lake Constance. The seller
>>assured me that the receiver was working fine and I have no reason to
>>doubt it. Anyhow I put it up today and there is a faulty synthesizer.
>>>>>>
>>>>>> I listend to a cw station at 7,021.80 with the 500 Hz filter.
>>>>>>When
>>I slowly turned the vfo knop upwards the cw pitch changed as expected.
>>When I reached 7,022.00 there was no change up to 7,029.99. Obviously
>>the actual receive frequency did not change between 7,022.00 and
>>7.029.99
>>>>>> I noticed the same with an SSB station at 7,191.80. The receive
>>frequency didn't change between 7,192.00 and 7,199.99
>>>>>> Receiving condition were very poor today and I didn't have much
>>time to evaluate the fault any further but it seems that this fault
>>exists every 10kHz at all freuencies xx,xx2.00 to xx,xx9.99
>>>>>>
>>>>>> As a first step I pulled every pc board one by one and put it
>>>>>>back
>>in but it didn't help.
>>>>>>
>>>>>> I have not yet downloaded the manual and schematics. This will be
>>the next step. I am well aware that the receiver is almost 40 years
>>old. I know that it has tantalum capacitors which are prone to
>>failure.
>>>>>>
>>>>>> If anybody experienced a similar fault I would appreciate any
>>>>>>hint
>>where I should start looking.
>>>>>>
>>>>>> Thanks in advance for any help.
>>>>>>
>>>>>> vy 73 Heinz DH2FA, KM5VT
>>>>>> ______________________________________________________________
>>>>>> Premium-Rx mailing list
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>>>>>> Help Page: http://mailman.qth.net/mmfaq.htm
>>
>>
>>------------------------------
>>
>>Message: 3
>>Date: Thu, 9 Jul 2015 15:24:38 -0700 (GMT-07:00)
>>From: "S. Schappert" <scottsch at ix.netcom.com>
>>To: "premium-rx at mailman.qth.net" <premium-rx at mailman.qth.net>
>>Subject: [Premium-Rx] Watkins Johnson 8617B- S1 CPU FS
>>Message-ID:
>>
>><7213976.1436480679087.JavaMail.root at elwamui-mouette.atl.sa.earthlink.net>
>>
>>Content-Type: text/plain; charset="us-ascii"
>>
>>An HTML attachment was scrubbed...
>>URL:
>><http://mailman.qth.net/pipermail/premium-rx/attachments/20150709/936f04da/attachment-0001.html>
>>
>>------------------------------
>>
>>Message: 4
>>Date: Mon, 13 Jul 2015 11:42:51 +0100
>>From: David Schofield <davesc50 at tiscali.co.uk>
>>To: premium-rx at mailman.qth.net
>>Subject: [Premium-Rx] WJ565 Plugins.
>>Message-ID: <rjs7aqv3qkv4xlwadtc9byru.1436784171414 at email.android.com>
>>Content-Type: text/plain; charset=utf-8
>>
>>
>>Hi All,
>>
>>I've just acquired a WJ-565A-1 receiver with a 20-90Mhz tuning head
>>fitted which is not an overly useful tuning range in the UK, although
>>it could be used as a demodulator for an Rx with a 21.5Mhz IF output.
>>
>>I'm wondering if anyone has any "spare" heads knocking around for one
>>of these that they would be willing to sell or swap for other receiver
>>related items?
>>
>>If so please reply off list.
>>
>>Cheers,
>>Dave. S.
>>www.ra1792.co.uk
>>
>>
>>
>>Sent from Samsung tablet
>>
>>------------------------------
>>
>>Message: 5
>>Date: Thu, 16 Jul 2015 18:14:00 -0400
>>From: Howard Ritter <hlritter at bex.net>
>>To: Premium-Rx at mailman.qth.net, boatanchors at mailman.qth.net
>>Subject: [Premium-Rx] Odd behavior by NRD-515
>>Message-ID: <1CED298C-E4F5-446F-8ADA-FB830302388D at bex.net>
>>Content-Type: text/plain; charset=utf-8
>>
>>Sorry for the semi-off topic post (somewhere between a Premium RX and
>>a
>>boat anchor!), but where else can you get this level of expertise?
>>
>>I have just had the embarrassing and expensive experience of having an
>>eBay seller return the Japan Radio Co NRD-515 receiver he?d bought
>>from
>>me, after finding severely reduced sensitivity between 600 and 1600
>>kHz. I?d never used it for BCB listening, so this problem had escaped
>>me.
>>
>>Briefly, this is a synthesized solid-state GC receiver that tunes a
>>lot
>>like the Collins 51-S1, with one knob to select one of 30 1-MHz ranges
>>and another knob to tune through the 1-MHz range that?s selected. It?s
>>possible, with continuous turning of the tuning knob, to move through
>>the ends of any 1-MHz range and into the next. Freq is digitally
>>displayed to 0.1 kHz. I simplistically envision the process as that of
>>synthesizing a base frequency as specified by the MHz knob and mixing
>>that with a variable freq determined by the tuning knob. That?s why I
>>couldn?t picture why a decrease in sensitivity would affect just part
>>of just a single 1-MHz band. I was skeptical until I got the receiver
>>back and put it on the air.
>>
>>Sure enough, I found just what he did. In tuning through the single
>>step from 599.9 kHz to 600.0 kHz, the background hiss goes from normal
>>to virtually absent, a very striking change. Very few stations are
>>received, weakly, up to around 1100, above which there is still
>>abnormally little atmospheric hiss but a few (strong?) stations are
>>heard. Continuing to tune upward, background noise reappears but
>>remains low up through 1599.9 kHz, after which it abruptly returns to
>>normal at 1600.0. It?s probably significant that this change in
>>frequency is accompanied by the sound of what I take to be a relay
>>clicking inside the radio, although there is no such sound at 600, or
>>anywhere else in continuously tuning except for 4999.9?5000.0
>>(although
>>when I switch ranges with the MHz knob, the relay clicks at 2, 3, and
>>4
>>MHz). I have tuned the entire spectrum with both the dial and the
>>UP?DOWN switch and have found no other place where the sensitivity
>>drops out like it does from 600 to 1599
>>.9. The decrease in, and return of, hiss occur whether I tune into the
>>0?1 MHz and 1?2 MHz bands with the MHz range knob or by twirling the
>>tuning dial, and whether I approach from above or below.
>>
>>The band of decreased sensitivity corresponds so closely to the MW
>>broadcast band that I wonder whether this is a coincidence. It would
>>make sense if the receiver were to automatically switch to a different
>>antenna input when it?s tuned to the BCB, and that could explain the
>>sound of the relay?except that there?s no separate antenna input for a
>>BCB or ferrite antenna. It may be significant that, outside the
>>affected frequency range, the background hiss drops markedly when the
>>antenna lead is disconnected?in fact, to the same level as the
>>background hiss within the affected range. And, within the affected
>>range, the hiss does NOT drop when the antenna is taken off. This
>>suggests to me that the RF from the antenna is not getting amplified
>>within that range. Still, why or how a problem could affect just part
>>of one tuning band and the adjacent part of another band, spanning
>>exactly 1000.0 kHz, remains a mystery.
>>
>>Any ideas?
>>
>>Thanks,
>>?howard n7exn
>>
>>
>>
>>------------------------------
>>
>>Subject: Digest Footer
>>
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>>Premium-Rx at mailman.qth.net
>>http://mailman.qth.net/mailman/listinfo/premium-rx
>>
>>
>>------------------------------
>>
>>End of Premium-Rx Digest, Vol 104, Issue 3
>>******************************************
>
>
>------------------------------
>
>Subject: Digest Footer
>
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>End of Premium-Rx Digest, Vol 104, Issue 4
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