How do you change the frequency of a magnetron?

You can change the frequency of a magnetron over a small range by changing the match of the output line. This is called frequency pulling and the data may be shown in the performance data by a Reike diagram which shows power, efficiency and frequency as a function of output match on a Smith Chart.

What is the frequency of a magnetron?

The magnetrons in domestic microwave ovens emit microwaves at 2.45 GHz (repeatable, each time the magnetron is switched on, to ±10 MHz) with bandwidths of only a few MHz [6].

How do you control back heating in a magnetron?

If the magnetic field is made larger than the critical field (B>Be), the electron experiences a greater rotational force and may return back to cathode quite faster. All such electrons may cause back heating of the cathode. This can be avoided by switching off the heater supply after commencement of oscillation.

How many running hours must be consumed before replacing magnetron?

Based on typical marine radar use, manufacturers recommend replacing magnetrons between 2,000 and 6,000 transmitting hours. However, CEAT found that magnetrons used in avian radar typically could be used for 12,000 hours of continuous operation before needing replacement.

Can a magnetron test good but still be bad?

Sometimes, when you’re troubleshooting a microwave, it can be tricky to tell whether or not the magnetron tube is bad. In the case with many GE microwaves, the magnetron can test good according to the filament resistance specifications yet fail when you’re actually trying to get the damn thing to heat up your bagel.

Why does magnetron use strapping?

The cavity magnetron is acts like a microwave oscillator and generates microwaves and it uses strapping to prevent mode jumping.

What is mode jumping in magnetron oscillator?

A magnetron when operated under pi (π) mode gives maximum output power and desired frequency. Some are quite close to one another, so that a π-mode oscillation which is normal for magnetron becomes (3/4)π mode oscillation. This is called as mode jumping. In order to avoid mode jumping strapping technique is used.