Wow, this thread got busy, Hi gang!
Well, to catch me up, yes - the radios' antenna connector WILL SHOW SHORT - why?
Locate L136 - toroid...Because it has a toroid wind "coupling" that allows DC and static to drain off and not get into the rest of the radio - think of it as a Hi-Pass Filter - Keeps DC and those noises off the antenna RX/TX line - or at least from doing any damages to the radio when you run a dipole - the static from the wind strumming thru the wires and it's open separator - it can generate enough voltages in static to poke - if not kill someone if they are not careful, let alone RF energy from an AMP and it's RF when it unkeys, that energy has to go somewhere to get quenched - might want to keep that outside of the radio.
Here's the location of what we're trying to show you...
Now, to me, the 560pF (561 Discs) are necessary, but not too much of a fussy REQUIREMENT.
There is a spot or them on the BASE lead below on the foil side. The MRF477 is a BEC configuration - meaning it's EMITTER is BOLTED to GROUND at the Chassis - and the Center leg of the part is solder to foil GROUND.
Note the use of Insulator on the part - above MRF477 is NOT using a Heatsink insulator - that is Heat sink goo - the part is botled to the rear panel ...
- What they suggest you do is to use a Mica insulator on that part - the EMITTER portion of this - to keep it's ground to the main foil pad below on the Foil side.
There is also your SWR problems - that is further over to the left - the SO-239 and it's made out of nickel and plated chrome - in an Aluminum HEAT SINK rear panel
- - so remember to also PROPERLY TIGHTEN the SO-239 connector, it uses a solder lug - keep it and properly solder it well to the foil ground. The rear panel is aluminum so it can oxidize and show a resistive impedance to RF that can and will inject SWR issues - hence my thoughts added to this thread...
So when problems do occur, be sure to keep an eye and ear out for erattic operation if the Final were to ever "latch up" - due to noise proximity that can make it go into self oscialltion - hence the 560pF's to keep RF off the Base lead - so don't put / place too much worry of Part exactly - but the LOCATION of them is important - just use some form of RF shunt to keep RF from ruining your day...
Part of the problem? Alloy and Galvanic events of corrosion - never gives good results - Steel and Aluminum don't mesh well...
