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Re: Aerotron-Repco Systems, Inc.
In a message dated 99-04-16 16:13:15 EDT, you write:
<< > > Hello: > > Has anyone used any equipment, i.e. Exciters or Receivers from ARS, Aerotron- >Repco Systems, Inc. > > I am seeking to build a repeater and am thinking about using their equipment. >Looking for honest opinion on the quality of this equipment. > > Thank You > Lindsay Hodgdon > >> Well, here's the scoop from Raleigh, NC where Aerotron started oh so many years ago. Raleigh ARS W4DW 146.640 ran an Aerotron base station modified for repeater operation; ran a homebrew controller for many years, then we upgraded to a RC-96 in about 1990. Over the last 9 years we have gone thru several upgrade receivers, PA's and other stuff, as we have had less and more people who worked in the plant interested in helping keep up the repeater. Latest big push was an MEGA model PA. We had a lot of trouble tho with the pair of finals going on us - they had a tendency to run too hot for the heatsink capability, the collector lead would actually heat up to the point of melting the solder, then of course when it cooled down it probably went to 'cold solder joint' status - eventually we even got to the point where the PCB trace would delaminate from the substrate. In retrospect, we were probably running it too close to an unstable point of excessive current draw for the amount of power we were trying to run. I can't remember the exact details, but I think it was a 100w package trying to run 50 watts or so - and the current draw on transistors running that much less than their rated power is typically non-linear - you draw more amps than you would expect for that power level, the excess goes to heat in the device, which has to go somewhere. Ex: 100w PA drawing about 7Amps, same PA running 50 watts might draw instead 5 to 6 amps. The figures are just ferinstances, to give you an idea. Add that a couple of busy evening nets and rag chew sessions, and you soon go from 'Intermittent Commercial Service' duty cycle to 'Continuous' duty cycle - and if the heat sink just ain't up to the Continuous job, you're in deep pucky. Among other things, we sometimes also had trouble with the little pins from the backplane to the Exciter and PA boards - which sit parallel to the backplane. They sometimes developed Hi-resistance. Our best solution when we had 'flakies' was to demount the board, and scrub it up and down on the pins a couple of times. Problem went away. For a while. About 1993, Repco bought out Aerotron's facilities, moved the operation to Orlando and called them ARS - From an other good friend who worked in there for a while, their technology advancement stagnated at about maybe 20 years ago. Mostly because as each succeeding company that owned Aerotron looked at what they had, they saw no need to put in money for R&D to advance their technology, and continued to suck out as much cash as possible, then sell off the shell (of the shell they had already bought). They got along OK for a long time 'cuz their equipment was very cheap to buy and they could slide in under the 'Big Boys' To be honest, don't know what they've done since they've been in Orlando, if they have updated their technology or not. The equipment may not be much worse than say, Spectrum, or so. Pedestrian, probably above the level I've seen from say, Ritron, and it's not a GE or Motorola (who, in all honesty, have both done some dogs.)( I know I'll get some flames for that!) I've rambled; take the advice of almost anyone on the list, get a >good< GE or Motorola and work from there. Replacement parts i.e. whole chassis can be picked up for a song at hamfests. Not so easy with Aerotron stuff. And if there are any current Aerotron - Repco employees here to dispute my opinions<, I will gladly stand aside.Chuk Gleason kb4mdz |
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List Server Maintenance
Kevin K. Custer W3KKC
List users,
I received this from the Onelist team and thought I would pass it along...... The ONElist system will be down for scheduled maintenance Saturday evening, April 17, 1999. We will be off-line from 10pm to Midnight Pacific Time while we upgrade the system. Email sent during this time will be stored and sent once we are back on-line. The ONElist Team Forwarded by: Kevin Custer The List Owner |
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Re: exposed dipole question
The Lacko's
One question. is this antenna on a mountain top or high hill??? You used
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the word valley in one of your posts. Could you require down tilt in the antenna??? just a thought, Scott At 04/16/1999 08:29 PM, you wrote:
From: NE2E@... |
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Re: exposed dipole question
farkle
Kurt what kind of repeater is it the FD has???Fred/Transcom Communications
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Kurt Bleich wrote: From: Kurt Bleich <kurt_bleich@...> |
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Re: FS: Micor low split mobile
John
Yes. There are directions at some sites on the web... can't tell you where
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just now, but I know several on this can point you in the right direction. You will need a different PA though, if you want to run much power. John
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Re: antenna question
The Lacko's
Kurt,
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The exposed dipole antenna is all we use on all of our commercial UHF repeater sites with great success. Scott At 04/16/1999 10:35 AM, you wrote:
From: Kurt Bleich <kurt_bleich@...> |
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Re: exposed dipole question
In a message dated 4/16/99 6:47:48 PM Eastern Daylight Time,
transcom@... writes: << > I have been watching some of the email in regards to these antennas, and now I > have a question. We have a VHF repeater for our fire depts in our county. > Compared to using other ham repeaters on 2m, this repeater seems to very deaf. > Would any characteristic of these exposed dipole antennas affect rx? This > repeater is all new and has been checked out several times, and I am making > the assumption that everything else is good.....I merely a 'user' on this > repeater. > > RX is 156.165 > TX is 150.995 >> Have then lower the antenna and check it, since everything is new i would check how the harness in the antenna was installed, maybe the installer to do a neat installation cut some cable off the harness, .... also check how the harness is connected to the folded dipoles because if its wrong it throws everything (signal) out of phase and they will cancel each other signal....i seen this before more then once and the swr was still Very low.. Exposed dipoles antennas properly installed perform great, better then the its cousins enclosed in a fiberglass radome, in my opinion.. FRED |
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2 Questions
Kevin Mitchell <[email protected]
Hi All,
I have two questions which I would like to ask for help. 1. I have a Motorola Mitrek low band transceiver (which was on 33MHz),which is being modified to operate on 29MHz, our 10mtr repeater. The problem is that somehow we have lost the service manual for it. Now the problem is that I have build a control head eliminator inside the radio as per the mods I had been given, these mods are from MJS Technology, by Cortney Buffington N0MJS. The instructions say to feed the COS from the base of Q406, or better still from TP"E". I have not been able to find TP"E" on the board anywhere, thus I need to be able to find it. 2. The above mentioned radio is capable of running 60w comfortably, which is the amount of power we would like to run full time on the repeater, however this is not advisable. Does anyone have a nice circuit of a full duty up to 100w amp that is suitable for repeater use. I can drop the power out on the radio to drive the amp, but I need to make sure it is very clean. I hope someone can help. Regards Kevin. ZL1UDD. |
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Re: Aerotron-Repco Systems, Inc.
critic
I had a two channel REPCO repeater that was built in 1980 uhf 25 watt that
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was going strong till last year when the local gov oopsed the tower in the vault and trashed the repeater... i also have several friends running the same machines no complaints the aerotron part of the company dose a big busniess in paging systems..... -----Original Message----- |
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Re: Crystals For GE MASTR II
John Lloyd
W8CQ,
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Ray is right, ICM will do the calculations for you, but if you want high side injection for the Receiver you need to specify it. VHF TX Crystal calculations are: Crystal Freq =Operating Freq/12 VHF RX Crystal Calculations are Crystal Freq=(Operating Freq - 11.2 Mhz)/9 UHF Tx Crystal calculations are: Crystal Freq=Operating Freq/36 UHF Rx Crystal calculations are: Crystal Freq=(Operating Freq - 11.2Mhz ) / 27 John Lloyd, K7JL Utah VHF Society Ray J. Vaughan wrote: From: "Ray J. Vaughan" <ray@...> |
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Re: Crystals For GE MASTR II
John Hackman
The CORRECT way to calculate the crystal frequency for any radio is to let International or whichever crystal supplier you are using do it. Any crystal manufacturer worth dealing with will do so, and will stand behind their calculations. Who will guarantee the accuracy of MY calculation? So I leave it to International.
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The sole exception to this rule is for really strange applications, like converting a standard Micor UHF mobile into a repeater with high-side receive. ......John WB4VVA ----- Original Message -----
From: Jeff Weinberg W8CQ To: Repeater Builder Sent: Thursday, April 15, 1999 9:31 PM Subject: [Repeater-builder] Crystals For GE MASTR II Hello All, I have a simple question (I think), but it may not have a simple answer. Recently I have acquired a GE MASTR II UHF radio for my repeater. I have seen 2 or 3 different ways to calculate the crystal frequency for this radio. This is a "painted handle" version of the radio. The one that DOES NOT have a tripler. What is the correct method for calculating TX/RX crystal frequencies for this radio? Thanks in advance, Jeff Weinberg W8CQ w8cq@... |
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Re: antenna question
John Lloyd
Kurt,
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Have you checked out the Feedline for Loss and or Damage. I would measure your transmitter power going into your feedline next to the transmitter and then climb the tower to the antenna and insert the wattmeter between the feedline and antenna and measure the power output from the transmitter. This will be your feedline loss. I would also check reflected power coming back from the antenna. This would be a good starting point. John Lloyd, K7JL Utah VHF Society Kurt Bleich wrote: From: Kurt Bleich <kurt_bleich@...> |
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Re: ge master II VHF to 220Mhhz
John Lloyd
Look at the page:
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for 220 modifications John Lloyd, K7JL KF4TNP wrote: From: KF4TNP <Bug1@...> |
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