Cassette decks RF shielding

[Makymak]

Well, I was recording with my Technics cassette deck and my cell phone rung. The phone was resting very close to the deck (how stupid I was!!!). But I didn't heard any interference. So, I guess it's shielded. This particular deck is an RS-B965. It was made at the early '90s when most devices of that era weren't designed to be immune to cell phone interference. Furthermore, I remembered that I never had heard any from my other Technics decks (of the same era). And that's strange as I can hear this interference on some more recent devices (like TV sets and amps). To tell the truth, I was surprised positively!

Are all decks shielded?

 

[J!m]

If they have a steel case that is tied to earth they are.

 

[vince666]

anyways, not sure if it happened mostly because I was checking/realigning decks and then the chassis cover was removed, but if there is a wifi router not too distant from the deck then the wifi signal does indeed influence the deck (I had noticed some random bumps in the response while doing REC/PB sweep tests)... so, I turned off the router's wifi and problem solved.

So, now, when I have to use my HiFi system (and especially while I am recording), I turn the wifi of my router off... the router, btw, is quite close to the HiFi system.
And, in doubt, I also keep my phone a few meters away.

 

[J!m]

The (most likely) switching power supply for that router could be contaminating your A/C line with added noise too.

 

[krellmk]

A/C Conditioner may help with the noise problem

 

[BlazeES]

Interesting share Vince. I experienced some of the same issues recently with my WiFi 6e / Mesh router that is located in my listening room. The latest Mesh routers with beam forming tech have some peculiar behaviors and I was picking up these weird pulsating noise bursts during playback. My Nak and my Sony decks never had RFI immunity problems and still don't - but the new addition // Mystery deck - is quite a bit older and obviously not immune to the wireless tech that came nearly 2 decades later ... and beyond.

You know you're old when you can remember using tin foil to improve television reception on a set of telescopic, rabbit ears ... and then you find yourself constructing a 'beam' barrier out of the same stuff 40+ years later, to quiet down a tape deck from 1979 ...

 

[Makymak]

I didn't expected an old declining format to be so well sophisticated engineered. In the '90s the interesting to cassette had started fading. I admire the cassette every day, a little more! I'm glad I came back.

 

[Miracle Mile]

I didn't expected an old declining format to be so well sophisticated engineered. In the '90s the interesting to cassette had started to fading. I admire the cassette every day, a little more! I'm glad I came back.

You are right..

I've enjoyed every second of rediscovering this format over the last years, and tried out all the in's & out's of it..

There is a lot of knowledge about this format here at Phoenix, so don't hesitate to ask.

You're welcome.

 

[Makymak]

You're welcome.

Thank you, Miracle Mile!!!

 

[vince666]

The (most likely) switching power supply for that router could be contaminating your A/C line with added noise too.

actually, since I had just discovered years ago that switching power supplies do add some hum to HiFi gear if they share the same AC plug/branch, when I've got the router I immediately removed its own switching power supply and replaced it with an oldschool non-switching one...

And, in fact, I meant just about the wifi signal when the router (with its inbuilt antennas) is close to the HiFi gear... luckily this router has a button to switch the wifi on/off then it's sufficient I switch wifi off while I still keep my desktop computers connected to the internet through ethernet wire.

 

[vince666]

Interesting share Vince. I experienced some of the same issues recently with my WiFi 6e / Mesh router that is located in my listening room. The latest Mesh routers with beam forming tech have some peculiar behaviors and I was picking up these weird pulsating noise bursts during playback. My Nak and my Sony decks never had RFI immunity problems and still don't - but the new addition // Mystery deck - is quite a bit older and obviously not immune to the wireless tech that came nearly 2 decades later ... and beyond.

You know you're old when you can remember using tin foil to improve television reception on a set of telescopic, rabbit ears ... and then you find yourself constructing a 'beam' barrier out of the same stuff 40+ years later, to quiet down a tape deck from 1979 ...

yes, Miles, some pulsating (and sort of random occurring) noises is just what I meant here... but, after all, I wasn't able to easily hear these noises... anyways, when doing REC/PB sweep measurements on decks they were visible on the frequency response plot (i.e. if the deck is just veeery close to the router)... and if the chassis cover of the deck is removed (i.e. when I service/realign it) then they are noticeable on the measurements also if I move the deck a couple meters from the router.

So, if I am simply listening, I often leave the wifi on (also because my smartphone is connected to the wifi) but if I have to take measurements or to record then I always switch the wifi off.

 

[Skywavebe]

Don't be so sure. Cell phones use very high frequency which propagates pretty well. The front of the deck is where interference will get in and that is usually covered by plastic or aluminum. It is best to get cell phones away from a tape decks while doing any critical recording as you might get the horsies in your recording which are packets of data being exchanged even when you are not using it. I have found as well some LED lighting emits different high frequency noise. One LED lamp I had was going at 472 KHz if you put a scope to it. This is why some tests have to be done with pull over lamps turned off.
I had a Radio station lose it's STL link with the transmitter one day. I took a Tascam 122 cassette deck over and some tapes but inside a building with a 5KW transmitter this was never going to work- too much RF in the air in this building and so this was not possible to work. You learn lessons all the time in Radio. Yes at ESPN Radio transmitter we had a tape deck going with a 50KW transmitter although it only put about 30KW up the pipe as we called it. The building was larger and much more clean design so probably less RF leakage from the Harris DX50. Guess where I was when 911 happened? At that transmitter as the Hancock was being evacuated. I had to switch AM1000 to a satellite source until things were quieted down.