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ge mastr IIe P/A
Posted: Thu Jun 01, 2006 3:36 am
by bayfire300
hello everyone,
i got a ge mastr IIe repeater off e-bay and i would like to boost up the power. does anyone know how to do this?.i cant find anything in the software to do so.
thanks
otto
Posted: Thu Jun 01, 2006 4:50 pm
by Will
Otto,
Did you look on repeater-builder.com ? They have a section on the IIe.
http://www.repeater-builder.com/ge/mast ... ments.html
Posted: Thu Jun 01, 2006 5:39 pm
by 440roadrunner
How much does it output?
How much is it rated for?
Why do you need more?
3 dB is DOUBLE the power
Posted: Sat Jun 03, 2006 7:00 am
by bayfire300
well when i got the repater it was supposed to be 100w then i found out the transmitter puts out 80 and i lose 20 through duplexer. so i figure i;ll get it back up to 100 and lose 20-30 through duplexer. i understand the 3db antenna increases power but i am at a crossroads on which antenna to get. further more the present duplexer only has 3 cans which makes the repeater suffer desense, so i am looking for a new duplexer.also i was told to stay away from a band pass only duplexer because it has a 2db insertion loss.as the repeater sits right now out of the duplexer is 60w.
thanks guys
otto
Posted: Mon Jun 12, 2006 4:45 pm
by bernie
My two bits worth:
The M-ll PA is not noted for reliability.
Yes, you can turn the power up, but at what cost for a db or so?
The system effects of output power is so overrated!
you can lose 3 db (1/2 power) and never notice it.
A 4 section Pass/Reject duplexer should do the job.
The choice of antenna is subject to many variables.
Here in Hawaii, a metallic antenna with exposed dipoles will eventually corrode and become noisy.
73's
Mastr IIe
Posted: Tue Jun 13, 2006 5:49 pm
by radios4bill
In the center of the PA there is a tiny BLUE pot! That is your output adjustment!
Posted: Thu Jul 06, 2006 5:01 am
by flecom
bernie wrote:My two bits worth:
The M-ll PA is not noted for reliability.
Yes, you can turn the power up, but at what cost for a db or so?
The system effects of output power is so overrated!
you can lose 3 db (1/2 power) and never notice it.
A 4 section Pass/Reject duplexer should do the job.
The choice of antenna is subject to many variables.
Here in Hawaii, a metallic antenna with exposed dipoles will eventually corrode and become noisy.
73's
how is the Mastr II PA not known for reliability?
as long as they are driven properly they will pretty much last forever at their rated duty cycle, or continous if its the continous version of the PA
Posted: Thu Jul 06, 2006 1:15 pm
by AEC
Don't worry about duplexer losses, you'll never know the difference regardless.
As to the MastrII being unreliable, I seriously doubt it, I helped a buddy in Michigan set up a Mastr II repeater over 15 years ago, it's still up and running!
As for the duplexer, get the best you can afford, I use Telewave's TPRD-4544, they are of the BpBr design and are six cavities as well, with -120 dBm isolation and are rack mount.
I have 6 of these duplexers and I would NEVER trade for others!
I've had 4 in commercial service for the past 7 years, and not one has failed, or failed to provide excellent service for me.
The Mastr II is a very rugged radio, and the P.A is no different!
Even with a loss of 20 or more watts, nobody will ever notice this, and surely not if the antenna choice is properly made as well.
If UHF, I most certainly would use a DB-420, that's about as rugged an antenna as you'll ever find, not to mention it's rugged construction and D.C grounding due to the design.
It's a folded dipole design, and the pattern is also easily reconfigured should you require a cardioid pattern over an omni pattern.
Excellent gain, extremely rugged and versatile...who could ask for more?
Mastr-II RF Amplifiers
Posted: Tue Jul 18, 2006 5:36 pm
by kc8epf
This amplifier has been in use for over 20 years. You final board will be stamped with an ID number typically 19D424006G* whic identifies power and frequency range. There are a couple of routine modifications to make to correct design defects that will make the unit "bullet-proof". I work on these units frequently and have for the last 27 years. Parts are available and they are cheap durible power. The IIe came in two versions early and late model. There are some issues with the early version which was made by IDA corp. Thelast version used two black modules which were reliable but required special fixtures to troubleshoot and repair. Don't worry aout power,worry about receiver specs and sensitivity and then the antenna. Power is always the last thing. You'll do fine.
Regards,
Mike