[Premium-Rx] Premium-Rx Digest, Vol 104, Issue 3

[Dan Robinson]

Re NRD 515 I would recommend Bob Sherwood who has years if experience modifying the receiver.  Also, Craig at KIWA...

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On Jul 16, 2015, 6:14 PM, at 6:14 PM, premium-rx-request at mailman.qth.net wrote:
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>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"
>>
>---------------------------------------------------------------------------
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>> Help Contact eMail:  paul at 8zo.com
>> Home Page:  http://www.premium-rx.org/
>>
>______________________________________________________________
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>
>------------------------------
>
>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>
>	
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>------------------------------
>
>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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>------------------------------
>
>End of Premium-Rx Digest, Vol 104, Issue 3
>******************************************