UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

GMB · 9th May 2021, 12:55 pm

Actually he is right. There are indeed rather badly specified devices on the market that claim exactly that.

They must be complete FM radios, but with no speaker!
Their sole purpose seems to be to display the frequency and the CTCSS - presumably after FM demodulation (they do not mention that).

It is not clear how sensitive they are - so not clear whether these are for telling you what you are transmitting or what you are receiving.

So what do you expect this to be used for?

A frequency meter is a fairly simple device, as modern things go. But decoding the CTCSS is a much bigger deal because first you have to demodulate the signal back to audio – and then measure the CTCSS while ignoring higher frequencies. Not so easy!

9th May 2021, 12:55 pm	#6
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,100	Re: Frequency counter and CTCSS decoder. Actually he is right. There are indeed rather badly specified devices on the market that claim exactly that. They must be complete FM radios, but with no speaker! Their sole purpose seems to be to display the frequency and the CTCSS - presumably after FM demodulation (they do not mention that). It is not clear how sensitive they are - so not clear whether these are for telling you what you are transmitting or what you are receiving. So what do you expect this to be used for? A frequency meter is a fairly simple device, as modern things go. But decoding the CTCSS is a much bigger deal because first you have to demodulate the signal back to audio – and then measure the CTCSS while ignoring higher frequencies. Not so easy!