Receiver RF Assembly

The coils are very difficult to de-solder, Dave places the assembly on and electric kitchen stove at the lowest heat setting. He does not get it hot enough to melt the solder but uses his solder gun to remove and replace the coils. I use a butane torch.

Back to 220 Mod

Remove the covers from the receiver rf assembly. Be sure not to mix you screws when replacing cover.

Note the location of the coax connections to the coils and remove the connection. Solder wick works well. When you replace the coax connections, replace them 1/8 turn closer to the soldered end of coils

The RF Assembly has 2 enamel coils and 5 silver coils. Coils L301/311/C301 and L305/315/C305 have taps on the bottom turns. Both taps were originally placed directly across from the solder ends of the coils. Dave replaced both taps 1/8 turn closer to the soldered end of the coil

After removing the turns, pull on the top and bottom of the coils until they are at the original length. When you replace the coils, the bottom should be just touching.

Specification for a GE Mastr II receiver is .5 micro volts for 20 db quieting. For approximate check, put an AC volt meter on the speaker with squelch open. For example, if voltage is 1.2 volts and you supply .4 mv on receive frequency to the receiver in order to get the voltage down to .12 (a factor of ten) that means your receiver requires .4 volts for 20 db quieting. Adding a preamp with ban pass cavity in front will give even better results.  I always get better results than the specifications.

2 meter repeater check:

50 watts into duplexer 43 watts out

.398 mv for 20 db quiting into receiver

.15 mv for 20 db quiting into band pass cavity and Pre Amp

Notes: 10/19/2017