SWR RF POWER METER MODEL YN-145

I've just obtained a swr RF power meter model yn145 and I would be really appreciative of any advice that maybe forthcoming about how to use it as I'm only ever used one with a switch. Many thanks for any advice that maybe forthcoming 73's CT4899

Hi Nathan,

This is a pretty generic vintage dual meter SWR unit and came marked with various model names.

It's easy to use for SWR, just set the variable control to zero, key up in a fixed power mode such as FM, then adjust the control clockwise until the left meter reads 'SET' at the full scale red line. Then you can simply read your SWR on the meter to the right.

This allows adjustment to be made and hence the claim across a wide range of frequencies as the circuitry inside (a simple stripline) is not frequency stable or compensated.

It's handy in that you wouldn't have to switch back and forth with a 'FWD/REF' style switch typical of single meter units and could leave it in line to constantly check your SWR. (Someone's bound to mention inline 'losses'. )

For reading power there would have been a look-up table in the user manual where you set the control depending on the frequency and power in use. Then the right hand meter wouldn't be reading SWR accurately anymore unless you happened to be kicking out 12W or 120W (The 'SET' point on the left meter.)

I'd just use it as a nice simple SWR meter.  


Hope that helps.

All the best,
Victor

Victor wrote:

Hi Nathan,

This is a pretty generic vintage dual meter SWR unit and came marked with various model names.

It's easy to use for SWR, just set the variable control to zero, key up in a fixed power mode such as FM, then adjust the control clockwise until the left meter reads 'SET' at the full scale red line. Then you can simply read your SWR on the meter to the right.

This allows adjustment to be made and hence the claim across a wide range of frequencies as the circuitry inside (a simple stripline) is not frequency stable or compensated.

It's handy in that you wouldn't have to switch back and forth with a 'FWD/REF' style switch typical of single meter units and could leave it in line to constantly check your SWR. (Someone's bound to mention inline 'losses'. )

For reading power there would have been a look-up table in the user manual where you set the control depending on the frequency and power in use. Then the right hand meter wouldn't be reading SWR accurately anymore unless you happened to be kicking out 12W or 120W (The 'SET' point on the left meter.)

I'd just use it as a nice simple SWR meter.  


Hope that helps.

All the best,
Victor

Thanks for the information, Victor. I'll do as you suggested and use it as a simple swr meter. 
73's Nathan