Icom IC-R75 clicking sound

Status
Not open for further replies.

LouCheese

Member
Joined
May 21, 2010
Messages
22
I had recently placed an order for an Icom IC-R75 and I was really psyched that it was scheduled to be delivered today...that is, until it actually arrived and I saw that the box had been dropped somewhere along the way.

The exterior box from the radio supplier was dented, and the top corner of the Icom box inside also had a slight dent. I hooked up the receiver to the power supply and an antenna, and set up the Icom for a basic scan through the entire frequency range. Basically, I just wanted to make sure everything was working.

I was able to pull in some stations and everything about the receiver's functions appear to be fine. The one thing I did notice, however, was that every time the receiver locked on to a station or some interference, it made an ever-so-slight clicking sound. This is the exact same sound that the receiver makes when powering up the unit. The click only occurs once when the scan stops immediately after a signal is found, and if the speaker was loud enough I probably wouldn't hear it. I would describe it as the sound of two pennies hitting each other in a jeans pocket.

Because this is my first shortwave receiver, and obviously, my first IC-R75, I thought I would ask the many IC-R75 users if the sound the receiver is producing is normal. I don't think the box was damaged enough to harm the unit, but given the price of the receiver, if the clicking sound is a sign of damage I'll want to contact the shipper and the radio supply company right away.
 

Kennrth

Member
Joined
Jul 24, 2006
Messages
144
Location
Bay Shore Long Island NY
Pretty typical behavior for a quality scanning hf receiver. Relays contacts are electrically quieter than a transistor for electrical throughput. But are mechanically noisier when switching and can be heard . Relays are chosen for good quality low ohm contacts , mechanic clicking noise is not a high priority in relay selection and can hold manufacturing costs down. .

Signals going through good relay contacts add no noise to signals flowing through them but transistors do add noise inherent in biased semiconductors.
Typically relays are found in the Pre Amp,AGC, RF input Nework, Bandpass and record output circuits etc . Grouping scan memory channels with like settings will keep the relay chatter down.
You may be hearing the external record relay actuating. This can be programmed to be off channel by channel.
So I think the radio is working but I would not accept it if returning it is an option. Mechanical Shock can cause latent failure (failure in the future) . Also most people do not have the test equipment to evaluate the receivers operation across the band. Needs a factory acceptance test . Also mechanical damage reduces resale value considerably.
Yes there are high quality solid state relays but are pretty expensive and get noisier with aging.
 

Kennrth

Member
Joined
Jul 24, 2006
Messages
144
Location
Bay Shore Long Island NY
This is a true story. A friend of mine had a Collins KWM-2 transceiver and had some annoying blemishes on it ( a cigarette burn to boot). It was of course used when it was bought. It was tested in the calibration lab where he worked and proved to be working very well. The unit was refurbished more than once. But he couldn’t help himself so he sold it and bought one that was “museum quality” . Paid a lot for it. And was working very poorly . Even had some wrong value components installed (looked like 4 oem parts from factory improperly installed) . This radio was a lemon for 40 + years probably sat in the corner because it could not be fixed. It took 3 professionals one of them was me, playing with it for several months in their spare time to make it functional. Several caps,tubes, missing components,incorrect value caps installed and a couple of tube sockets got it up and running. Suspect there were some ECO’s missing. Neutralizing was too sensitive. And could never figure out what caused it. Sold it for less and bought another one that looked fair but worked like a champ.
Murphy’sLaw.
The point is if you can’t return it , That could be a blessing in disguise.
 

LouCheese

Member
Joined
May 21, 2010
Messages
22
Thank you sir for your replies. I figured with such a sophisticated piece of equipment that is still more or less set at the default settings that this might be ordinary. I'm going to play around with the receiver settings tonight and I'll zip up all of the photos I took of the boxes and send it to the supplier tomorrow.
 
Status
Not open for further replies.
Top