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 Post subject: JRC repair
PostPosted: Jan Fri 29, 2016 1:50 am 
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Location: Katy, Texas
I realize this isn't vintage but hopeing someone could help. I have two JRC receivers. NRD-525 and NRD-535. Both of them seem to function but will only faintly recieve the strongest signals with a lot of back ground static. Is there anyone that these can be sent to for repair that is reputable and reasonable cost wise?

Thanks
Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 2:08 am 
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Location: Somers, CT
Try this guy:

http://www.landaircom.com/service.html

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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 3:37 am 
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thanks.. i'll give him a call tomorrow.


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 4:07 am 
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The fact that you have two receivers known to be very well made show the same defect would leave me to believe that the fault lies elsewhere. Try a different antenna perhaps, or question your operating technique, attenuator turned on, all frequencies or one segment of the HF bands only?

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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 5:10 am 
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you know... i suppose it is possible they are not the simplest radios. I need to spend some time with an owners manual. I'll see if I can find one on the internet.

Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 3:20 pm 
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majoco wrote:
The fact that you have two receivers known to be very well made show the same defect would leave me to believe that the fault lies elsewhere. Try a different antenna perhaps, or question your operating technique, attenuator turned on, all frequencies or one segment of the HF bands only?


I managed to find an online manual for the 525. with 6 feet of wire hanging out the back I would say the receiver is on par with a reception I would expect from a one tube receiver :).

I'm pretty sure there is something wrong with them. The two models are very similar and probably have an identical fault.

Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 3:34 pm 
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Steve,

Have you tried cycling the low/high Z switch on the back panel a few times because you may just have a dirty switch issue. Try your short wire on both sets of inputs making sure that the switch is set to select the input with the connected piece of wire.

These JRC radios are very well shielded due to the company history of providing shipboard gear and the tuned front end may not like the match with your very short piece of wire. Try a better antenna if possible.

Rodger WQ9E


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 8:16 pm 
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These are proper communications receivers with low impedance antenna connections and certainly will NOT work with 6 feet of wire hanging out the back! Domestic tube radios with high impedance input connections are designed to work with short bits of wire. You need to erect a proper shortwave antenna. I have an NRD 515 - a predecessor to your receivers and I use a windom of 60ft/30ft with a 9:1 balun in the centre to get worldwide reception.

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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 9:13 pm 
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Hi Marty,

I also have a NRD-515, built like a tank isn't it :)

Rodger WQ9E


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 10:35 pm 
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rsingl wrote:
Steve,

Have you tried cycling the low/high Z switch on the back panel a few times because you may just have a dirty switch issue. Try your short wire on both sets of inputs making sure that the switch is set to select the input with the connected piece of wire.

These JRC radios are very well shielded due to the company history of providing shipboard gear and the tuned front end may not like the match with your very short piece of wire. Try a better antenna if possible.

Rodger WQ9E


Thanks Rodger, For the sake of clarity ... I'm not really expecting much from my short antenna. Its really just a test to see if the radio is working or not. I have tried both inputs and cycled the switch quite a bit. I've also confirmed the signal is completely lost when the switch is in the wrong position.

Not expecting to dx but reception on the broadcast band ought to be decent even with 6 feat of wire I would think. Last night wwv at 5.0 was barely audible.

Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Fri 29, 2016 10:42 pm 
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majoco wrote:
These are proper communications receivers with low impedance antenna connections and certainly will NOT work with 6 feet of wire hanging out the back! Domestic tube radios with high impedance input connections are designed to work with short bits of wire. You need to erect a proper shortwave antenna. I have an NRD 515 - a predecessor to your receivers and I use a windom of 60ft/30ft with a 9:1 balun in the centre to get worldwide reception.


Thanks for the advice Marty.

Unlike the 515 the 525 and 535 have switch selectable hi and low z inputs. The manual states "if a high impedance antenna such as a 4-to-6 M long vinyl coated wire is to be used connect it to the MF HF HI-Z terminal on the rear panel. In this case the ANT switch must be put to the Hi-Z position. I've always wanted a NRD-515 or a Drake R-7 and when I saw these two JRC i thought....close enough and they were cheap enough to take a chance on untested.


I bought both of these units from the same place with no history of them. I suppose it is possible a lightning strike nearby may have damaged both receivers. I will however try a longer that 6 foot antenna this weekend. My Sony ICF-6800W has not issue with receiving very will with just its included telescoping antenna.

Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 1:53 am 
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Right now it is winter in the northern hemisphere. Frequencies above about 7 mHz are pretty dead at night--especially if you live near or in a city where the noise floor can be fairly high. I have some great radios and after night falls, they don't do much--especially with a small antenna. With my fan dipole up at 5,300' elevation in the mountains, away from most noise sources, the 20 meter band has almost nothing after evening falls.

Norm

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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 5:08 am 
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ok gents.

Being one that has never actually had a radio of this quality before I must admit I didn't know what I was doing :). Thank you all for your input.

I took both receivers upstairs and hook them up to my "antenna". It consists of connectivity to the drip edge running around the perimeter of my roof.

The 525 sprung to life on 80 and 40 meter ham bands and seems to work just fine. The RF Gain seems to be flaky in that it "peaks" at about 10 o'clock with the AGC turned off.

The 535 is much less noisy than the 525 and works even better. it too has a flakey RF Gain pot but its pot clearly just needs a shot of some contact cleaner.

Now then, I have two working JRC receivers the may just need a minor tune up. I believe for sure all the 535 needs is the RF gain pot cleaned.

I'm stoked. These radios make the ICF-6800W seam like a toy in comparison and I thought that was a nice radio.

Live and learn and thank you all for your help. Now to decide which off all these is the keeper. Or do I start a communications receiver collection... lol.

Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 5:15 am 
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Quote:
The RF Gain seems to be flaky in that it "peaks" at about 10 o'clock with the AGC turned off.

Yes, it will. You aren't using the RF gain vs. AGC correctly. At that point where the RF gain control "Peaks" is the point where the AGC would be setting itself to. If you go to manual and turn the RF gain past that point, the receiver is overloading and significant distortion and noise will be apparent.
Leave the AGC on most of the time - you can reduce the gain with the RF gain control to remove background noise from intermittant signals or 'pumping' with CW signals.

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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 3:15 pm 
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majoco wrote:
Quote:
The RF Gain seems to be flaky in that it "peaks" at about 10 o'clock with the AGC turned off.

Yes, it will. You aren't using the RF gain vs. AGC correctly. At that point where the RF gain control "Peaks" is the point where the AGC would be setting itself to. If you go to manual and turn the RF gain past that point, the receiver is overloading and significant distortion and noise will be apparent.
Leave the AGC on most of the time - you can reduce the gain with the RF gain control to remove background noise from intermittant signals or 'pumping' with CW signals.


Thank you for the reply Marty. I guess i'm learning more and more here? Do you think the effect would actually cause the 535 to cut out and I am mistaking overload for a dirty pot? The Audio Gain is also scratchy.

Steve


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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 8:33 pm 
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IMHO I would "exercise" all the controls for a few turns and see if it improves first. If they have been in storage for a while it may be that all the contacts have become slightly oxidised.

If the internal connections that are used on the NRD 515 are used in yours too, that is, cheap phono style sockets and leads, then I would unplug and plug back in all those once or twice too - they are a known problem.

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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 8:47 pm 
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When my JRC NRD 515 went deaf after a decade of non use, the problems were traced to the foam rubber used to support the internal mechanical filter components. It had turned to goo; which destroyed the bandwidth and insertion losses.

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 Post subject: Re: JRC repair
PostPosted: Jan Sat 30, 2016 11:51 pm 
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Those jrcs, in particular the 535, are Cadillacs of the swl world. The 525 will likely be best at utility dxing due the audio quality, the 535 can be adjusted for sparkling audio reproduction. I ran a 535 against my beloved Drake R8 on the same signals, same antenna, and closest approximation of filter bandwidth and the 535 was far superior in audio quality, at least in my mind.


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 Post subject: Re: JRC repair
PostPosted: Jan Sun 31, 2016 12:19 am 
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The 515 is variously reported to have "muddy" audio, someone said it sounded like having a blanket over the speaker. My JRC speaker was open circuit so I replaced with one the right size and filled the cabinet with speaker wadding - improved the audio no end. Perhaps the wadding stopped tha cabinet vibrating.
I also made up a buffer stage for the AM detector which also affects the SSB signal too. It's all in the 'files' section of the Yahoo NRD 515 group.
I also carried out the Kiwa capacitor replacement mod but I didn't think it made much difference.

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 Post subject: Re: JRC repair
PostPosted: Jan Sun 31, 2016 1:35 pm 
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Location: Rochester, NY.
Funny how this dissolved into a 515 topic. I don't mean to hijack, but a SK friend's family gave me his NRD-515 radio to keep it working. I felt honored to get his radio. He kept all the paperwork and installed the extra filter and headphone jack. It has the factory speaker and memory unit.
I use it for MW/SWL.
It was factory-serviced a couple of times. The 1st time, an RF FET got knocked out and the receiver was returned in not much better shape. The 2nd try was a successful repair. He got to speak with the servicing technician the 2nd time.
Yes the company has an impressive history and product. At my age, I wouldn't consider 1980's 'vintage' :mrgreen: but with a metal faceplate and cabinet, it qualifies as a 'boatanchor' albeit a solid-state one.
I must have over-looked the Yahoo group, I mostly use the QTH.net and eHam sites. Not much discussion activity for these rigs anymore, but they are still out there being enjoyed.


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