Skipp, I just looked at a spare Mastr Exec II PA, and I can suggest a means to quickly identify which board you have. At each of the four final transistors (4104P1), there are two 39 ohm resistors (orange-white-black-gold) and four resistors that are specific to the bandsplit. The attached photo shows those four resistors outlined in blue, on a 19D417927G4 PA. The color code is as follows:
1.2 ohm (brown-red-gold-gold) 42-50 MHz (as shown in the photo) 2.0 ohm (red-black-gold-gold) 36-42 MHz 3.9 ohm (orange-white-gold-gold) 30-36 MHz 6.8 ohm (blue-gray-gold-gold) 25-30 MHz You probably don't need to have the color codes explained, but I'm getting forgetful due to my age and infirmities, and I need to remind myself! 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of skipp025 Sent: Sunday, September 13, 2009 10:36 AM To: [email protected] Subject: [Repeater-Builder] Re: GE LB VHF RF Amplifier Drive Level? basic specs? Thank you Eric and Andy... Andy, I just learned and realized how the Control F feature works and that will become a huge help in future searching. Man... for never previously having a need to research and source out GE LBI Manuals much I must say the Repeater Builder Web Page GE LBI listing is pretty darn impressive. I found the 100 watt Low Band Transmitter Manual before Eric provided the PA PDF URL so now I have both. I saw in the transmitter manual the normal "nominal" drive is about 250mW. (thank you Eric) I can't find the numbers listed below on the board with the exception of a large 6 etched out of copper on the board. I might now assume the unit is the 30-36 MHz unit mentioned below unless the pc board label is printed somewhere not within obvious view. If the PA is the 30-36 MHz range... I'm starting to wonder how well it will work at 29.6 for Amateur Radio 10 Meter Repeater work? Again thank you for your replies... I'm still sorting through the remaining flea market "stuff". cheers, skipp > Skipp. > The 19B219688G6 is a heat sink assembly that is common > to four PA assemblies and PA boards: > > 19C321295G5 and 19D417927G1, for 25-30 MHz > 19C321295G6 and 19D417927G2. for 30-36 MHz > 19C321295G7 and 19D417927G3. for 36-42 MHz > 19C321295G8 and 19D417927G4, for 42-50 MHz > > The PA is rated at 100 watts, and all use the same > transistors. I may be able to get more information, > once I know which board you have. > > 73, Eric Lemmon WB6FLY > > > -----Original Message----- > From: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > [mailto:[email protected] <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of skipp025 > Sent: Sunday, September 13, 2009 8:44 AM > To: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > Subject: [Repeater-Builder] GE LB VHF RF Amplifier Drive Level? basic specs? > > > > On the way home from yesterdays Lincoln, CA. Ham Swap > I noticed a bunch of surplus GE Radio Gear just "up and > jumped into the back of the truck". > > Two of the hitch-hiking items were GE VHF RF Amplifiers, > looking a lot like a GE Master II Mobile decks factory > mounted into a frame used in a base/repeater application. > > The RF Decks appear to be VHF Low Band units with the > printed part numbers of PL19B219688G6 REV on each. The > final output devices are 4 labeled C4104P1 transistors > as is the single driver. The remaining first input device > is a transistor labeled C6965P1. > > So... can anyone tell me the basics about this PA Model? > > Drive Level? > Realistic Output Level? > > The output of the PA goes toward a covered T/R Relay section > in the chassis/frame corner where I see connections for a > receiver port. Is the T/R Relay normally powered/energized > with each transmission to route the RF Amplifier to the Antenna > (output) Port? All the RF Connections appear to be the RCA > type... > > Unlike Motorola RF Amplifiers... I'm not seeing an RF Power > Stage Control Voltage line/wire/connection point from/on the > chassis? > > The two chassis that came home with me look to be real cookers > for something on low band... if I can get them to work. > > Thank you in advance for your replies... > > cheers, > skipp >
