R8600 R8600 10 MHz ref input level

[Teotwaki]

First thing I did was RTFM I also Googled a bit with no luck.

I've not seen an actual number stated that comes from Icom. I'll have to ping them after the holidays.

For starters I measured the Icom's 10 MHz output level and it's at 0 dBM when the connector is switched to the "out" mode.

Page 11-7 in the manual points out a nifty feature where the radio's frequency readout will blink if the external 10 MHz reference quality is poor or if the level is too low. Using my HP8657A signal generator I found that the 8600's minimum starting level seems to be -35 dBM.

Has anyone read anywhere that Icom has specified a maximum limit in order to avoid damage to the 10 MHz reference input circuitry? For now I will assume 0 dBm since that is what Icom chose for an output level.

To calibrate the 8600 I plan to use my GPS Disciplined Oscillator's output but it measures at +18 dBm So it'll have to be attenuated by 18 dB for now.

Jim

 

[WPXS472]

The Icom manual states that the required 10 MHz input is -10 dBM. I have wondeered about what an acceptible level would be as well. Looks like 0 dBM should be OK. I would have thought that at this price level, they would have used a nice OCXO, but they used a TCXO instead. I guess they didn't want users to have to wait for warmup.

 

[prcguy]

I'm feeding my 8600 around -10 to -12dBm. I have a GPSDO feeding a 10MHz filter then 20dB attenuator then 2-way divider to my 8600 and IC-9700, which both specify -10dBm input level.

The Icom manual states that the required 10 MHz input is -10 dBM. I have wondeered about what an acceptible level would be as well. Looks like 0 dBM should be OK. I would have thought that at this price level, they would have used a nice OCXO, but they used a TCXO instead. I guess they didn't want users to have to wait for warmup.

 

[Teotwaki]

The Icom manual states that the required 10 MHz input is -10 dBM. I have wondeered about what an acceptible level would be as well. Looks like 0 dBM should be OK. I would have thought that at this price level, they would have used a nice OCXO, but they used a TCXO instead. I guess they didn't want users to have to wait for warmup.

Thanks WPX472! Using the index in the manual I paged to 11-7 but never explored further to discover 16-1. I wrote that page in the index so I won't forget again. My 8600 is fairly new so I'm having fun learning about it.

Jim

 

[Teotwaki]

I'm feeding my 8600 around -10 to -12dBm. I have a GPSDO feeding a 10MHz filter then 20dB attenuator then 2-way divider to my 8600 and IC-9700, which both specify -10dBm input level.

It's your fault I bought this radio!!

 

[WPXS472]

I'm feeding my 8600 around -10 to -12dBm. I have a GPSDO feeding a 10MHz filter then 20dB attenuator then 2-way divider to my 8600 and IC-9700, which both specify -10dBm input level.

That sounds like a good setup. I don't remember if they specify sine or square. I was thinking of running my 10 MHz from a GPSDO through a squaring circuit first. They probably want sine though. If they wanted square, it would probably be at 5 or 3.3 volts.

 

[prcguy]

It probably won't be the last $$ I spend of yours.

It's your fault I bought this radio!!

 

[prcguy]

My GPSDOs are sine except for the Bodnar, but that is a special purpose unit that outputs anywhere from 400Hz to 810MHz.

That sounds like a good setup. I don't remember if they specify sine or square. I was thinking of running my 10 MHz from a GPSDO through a squaring circuit first. They probably want sine though. If they wanted square, it would probably be at 5 or 3.3 volts.