[Repeater-Builder] GE mastr II station PA
I am looking for some help with a UHF GE Mastr II base I just acquired. I've never worked on one of these before and have no knowledge as to what mods need to be done. My unit currently is on 416.550 and I need to move it up to 444.425 but have some questions before I begin. My biggest concern is about the Power Amp. I have a 19D321347 G5 Rev N PA board which according to LBI-30213E is a 406-420 Mhz 40 watt PA. There seems to be another version of the same board number except it is a G9 and the LBI says it is for 420-450 Mhz but I can't find a listing with the differences between them. The LBI shows both G5 and G9 range boards with the same components listed as the (LL) designation supposedly covering the entire 406-450 range. Can anyone enlighten me as to the difference between the G5 and G9 version of the 40 watt PA?. Will the 406-420 PA board work in the 444 range? If not can anyone advise what mods need to be done so it will? My PA also has a 19D327024 G1 filter which shows it is used in both the 406-420 range as well as 420-450 range. However when the G9 version of the PA board is used it shows it covers 420-450 Mhz. Will I need to mod the filter to get the 444 Mhz signal to pass? There again I find no differences to the filter board when used in the different segments. I appreciate any help Larry - N7FM
Re: [Repeater-Builder] GE mastr II station PA
My suggestion is to get a different radio with the 88 split. Otherwise you've got a lot of work ahead. Chuck WB2EDV - Original Message - From: iamcranked la...@thunderbolt.net To: Repeater-Builder@yahoogroups.com Sent: Tuesday, March 10, 2009 4:55 AM Subject: [Repeater-Builder] GE mastr II station PA I am looking for some help with a UHF GE Mastr II base I just acquired. I've never worked on one of these before and have no knowledge as to what mods need to be done. My unit currently is on 416.550 and I need to move it up to 444.425 but have some questions before I begin. My biggest concern is about the Power Amp. I have a 19D321347 G5 Rev N PA board which according to LBI-30213E is a 406-420 Mhz 40 watt PA. There seems to be another version of the same board number except it is a G9 and the LBI says it is for 420-450 Mhz but I can't find a listing with the differences between them. The LBI shows both G5 and G9 range boards with the same components listed as the (LL) designation supposedly covering the entire 406-450 range. Can anyone enlighten me as to the difference between the G5 and G9 version of the 40 watt PA?. Will the 406-420 PA board work in the 444 range? If not can anyone advise what mods need to be done so it will? My PA also has a 19D327024 G1 filter which shows it is used in both the 406-420 range as well as 420-450 range. However when the G9 version of the PA board is used it shows it covers 420-450 Mhz. Will I need to mod the filter to get the 444 Mhz signal to pass? There again I find no differences to the filter board when used in the different segments. I appreciate any help Larry - N7FM Yahoo! Groups Links
RE: [Repeater-Builder] GE mastr II station PA
Can anyone enlighten me as to the difference between the G5 and G9 version of the 40 watt PA?. If I remember right, one capacitor is changed, and one is either added or deleted. I have GE's mod sheet that tells you how to convert a 40 watt 406-420 to a 420-450. Email direct if you want a copy. Will the 406-420 PA board work in the 444 range? Only the 40 watt board, and only a couple of components like I mentioned. The PA board (if you had a 100 watt PA) doesn't require modifications. Will I need to mod the filter to get the 444 Mhz signal to pass? I'll have to look at the schematics again; I thought there was a difference between the low-pass filter boards but maybe not. It might be easier just to sub in an LPF out of a 450-470 radio since they're easy to come by. --- Jeff WN3A
RE: [Repeater-Builder] GE mastr II station PA
My biggest concern is about the Power Amp. I meant to comment on this - the power amp is the least of your worries. The exciter and receiver is where you'll likely have bigger problems. Here again, it's probably easier to find 450-470 boards and swap them out. --- Jeff
Re: [Repeater-Builder] GE mastr II station PA
I have moved several GE Mastr II 40 watt units up from the 417 mHz area to the 440 mHz area as repeaters. The exciter tunes up OK to the higher frequency, but the receiver front end and LO multiplier will not tune. I use LOW side injection for the LO string and modify the helical resonators in the front end. I remove all the helical resonator coils and remove one quarter turn from each coil to get it to tune up into the 440 band. The modified receiver will tune from 420 through 450 with this mod. A better approach is to obtain a 450-470 mobile and exchange the LO and front end modules. No modification is required to the helical resonators on the 450 to 470 radios. Be sure to use HIGH side injection for the receiver with the 450-470 front end. On the low pass filter for the transmitter, I paralleled a #20 bare wire with the wire already in place coupling the sections of the filter together and the reduced inductance moves the filter up enough into the band to pass 450 with no problem. I did not change anything else in the amp. 73 - Jim W5ZIT --- On Tue, 3/10/09, iamcranked la...@thunderbolt.net wrote: From: iamcranked la...@thunderbolt.net Subject: [Repeater-Builder] GE mastr II station PA To: Repeater-Builder@yahoogroups.com Date: Tuesday, March 10, 2009, 3:55 AM I am looking for some help with a UHF GE Mastr II base I just acquired. I've never worked on one of these before and have no knowledge as to what mods need to be done. My unit currently is on 416.550 and I need to move it up to 444.425 but have some questions before I begin. My biggest concern is about the Power Amp. I have a 19D321347 G5 Rev N PA board which according to LBI-30213E is a 406-420 Mhz 40 watt PA. There seems to be another version of the same board number except it is a G9 and the LBI says it is for 420-450 Mhz but I can't find a listing with the differences between them. The LBI shows both G5 and G9 range boards with the same components listed as the (LL) designation supposedly covering the entire 406-450 range. Can anyone enlighten me as to the difference between the G5 and G9 version of the 40 watt PA?. Will the 406-420 PA board work in the 444 range? If not can anyone advise what mods need to be done so it will? My PA also has a 19D327024 G1 filter which shows it is used in both the 406-420 range as well as 420-450 range. However when the G9 version of the PA board is used it shows it covers 420-450 Mhz. Will I need to mod the filter to get the 444 Mhz signal to pass? There again I find no differences to the filter board when used in the different segments. I appreciate any help Larry - N7FM
