Hi Group...
My R2600 works fine w/ internal reference oscillator. Just added known-working external 10 Mhz TCXO, flipped the toggle swithc on the bottom, and the analyzer will power up w/ fan, but no screen or other function. This is similar to recent another post, but in reverse...in this case I'm trying to add an external TCXO and the system won't boot. I know the external reference is working, as I am able to monitor a very strong storng signal at 10 Mhz on an HF receiver. The R2600 user manual has very scant info on adding and calibrating an external reference.
Any suggestions on procedure, troubleshooting?
Thanks and regards,
DT
R2600 W/ EXTERNAL 10 MHZ REF
Moderator: Queue Moderator
Re: R2600 W/ EXTERNAL 10 MHZ REF
In addition to prior post...the "strong signal" on 10Mhz is not WWV! I can hear WWV but the TCXO cover it up and is zero beat within 10 Hz or less of the WWV carrier.Lots of 10Mhz signal going into the R2600...does it need to be padded down?
DT
DT
Re: R2600 W/ EXTERNAL 10 MHZ REF
The typical external reference is capable of delivering 0.5 to 1.0 VRMS into 50 ohms.
You could measure yours with an oscilloscope, RF voltmeter, or the 2600 itself. The 2600 would seem to be the easy way.
Set the 2600 to run on its internal reference. Select monitor mode. Set the monitor frequency to 10.000 MHz. Choose RF I/O and 20 dB attenuation. Select the spectrum analyzer display. Connect your external reference to the RF I/O port. If your display shows that the external reference has an amplitude of 0dbM to +10 dBm it is probably fine.
If the external reference is OK then is is possible that your 2600 has a fault in the INT/EXT switch or reference circuitry.
You could measure yours with an oscilloscope, RF voltmeter, or the 2600 itself. The 2600 would seem to be the easy way.
Set the 2600 to run on its internal reference. Select monitor mode. Set the monitor frequency to 10.000 MHz. Choose RF I/O and 20 dB attenuation. Select the spectrum analyzer display. Connect your external reference to the RF I/O port. If your display shows that the external reference has an amplitude of 0dbM to +10 dBm it is probably fine.
If the external reference is OK then is is possible that your 2600 has a fault in the INT/EXT switch or reference circuitry.
Re: R2600 W/ EXTERNAL 10 MHZ REF
Thanks for the quick reply and the step-by-step! Will do some measurements and let you know how it goes.
Rgds,
dt (also ex-MOT)
Rgds,
dt (also ex-MOT)
Re: R2600 W/ EXTERNAL 10 MHZ REF
Hi XMO...
Measured levels and the R2600 measures the TCXO output at -16.6 dBm, lower than the 0 to +10 dBm you ballparked.
How forgiving is the R2600 of low reference level? Am I splitting hairs at -16dBm, or is this totally out of the ballpark?
Looks like I may have to tear into either the R2600 or the TCXO (a Ballantine freq meter) to goose up input sensitivity or output gain?
Thanks...
dt
Measured levels and the R2600 measures the TCXO output at -16.6 dBm, lower than the 0 to +10 dBm you ballparked.
How forgiving is the R2600 of low reference level? Am I splitting hairs at -16dBm, or is this totally out of the ballpark?
Looks like I may have to tear into either the R2600 or the TCXO (a Ballantine freq meter) to goose up input sensitivity or output gain?
Thanks...
dt
Re: R2600 W/ EXTERNAL 10 MHZ REF
The 2600 needs the external reference signal to be in the range from 70 millivolts to 1 Volt RMS.
The lower limit [70 mV] across 50 ohms is approximately -10 dBm so yours is more than 6 dB too low.
Since the upper limit of 1 Volt RMS is +13 dBm, a signal in the range from 0 to +10 is comfortably above the minimum and does not exceed the maximum recommended value.
The lower limit [70 mV] across 50 ohms is approximately -10 dBm so yours is more than 6 dB too low.
Since the upper limit of 1 Volt RMS is +13 dBm, a signal in the range from 0 to +10 is comfortably above the minimum and does not exceed the maximum recommended value.