Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- Repeater-Builder
- Messages
Search
|
Re: A Challenge.. / and another with a Mitrek
mch
I wrote (originally):Then Joe Orrico WB6HRO wrote: But how would a receiver connected to an IFR differ in voltage from a receiver connected to a duplexer? In case I gave the wrong impression, the unit is still at the repeater site - the only change is that the RX antenna was 'pulled' from the duplexer and plugged into the IFR. The TX is still connected to the duplexer, and the power (both TX and supply) is exactly the same. It's as if the duplexer is severely mis-tuned. And since I didn't mention this either, it works flawless on a Mastr-II - RX sensitivity is great both direct and through the duplexer, so the duplexer is tuned correctly. (In fact, it has never been changed from the factory) I will check the voltages, though. The only problem is that the troubleshooting must be done at the repeater site. The duplexer is the one in normal use. This is almost like reverse desense - perhaps there was a slight spur when the TX was inactive that severely desensed the RX??? I didn't check that. Thanks for the response, Joe, KR3P |
|
Re: Squelch on GE Mastr II
mch
There are jumper changes when you install/uninstall a CTCSS board. I
toggle quoted message
Show quoted text
know one is on the front/left side of the system board (with the handle facing you). That is the PTT control jumper that selects normal PTT vs Delayed PTT. With the jumper in the 'CTCSS' position, the unit will not transmit (using the PTT line) without the CTCSS board actually being in the unit. If you jump 10V to the oscillator control, the unit will TX anyway and this jumper doesn't apply since that point is after the jumper. I don't recall where the others are offhand. I don't have the manuals at home. Check the voltages at the points labeled RX MUTE - that's on the connector on the system board that is on the extreme right. SQ Disable should only disable CTCSS and should not itself open the squelch but RX MUTE will open the squelch. When squelched, RX MUTE is a logic low (0V). One word of caution if you don't already know - the label on that connector (J903?) is *usually* offset a little from the pins, so make sure you are looking at the correct pin. Well, back on topic, the unit should not open squelch just due to the removal of the CTCSS board. Unplug the board - the RX becomes CSQ with no jumper changes necessary. The RX MUTE (NOT CAS) will even work as a CSQ unit. Of course, CAS always follows the receiver regardless of CTCSS presence. Does the unit receive on the selected frequency? OH! Check your 10V supply! That could open the squelch. It has to be 10V +/- a few hundredths. I want to correct something I said earlier. I believe an *internal* squelch WAS an OEM option on a Mastr-II. It was rare, but I think I do remember seeing a unit that had one. The only control on the C/HD was volume and on/off. Ed Bathgate, RMA Repair Dept x8785 wrote:
|
|
Re: Squelch on GE Mastr II
edriddle
the squelch circut is all ready there. you merely need to put in a pot to
toggle quoted message
Show quoted text
set it 73 ed n4ale look at the ge page on the internet and it will tell you where and how. At 04:11 PM 3/22/99 -0500, you wrote:
From: "Ed Bathgate, RMA Repair Dept x8785" <ed@...> |
|
Re: Squelch on GE Mastr II
Ed Bathgate, RMA Repair Dept x8785
This is a mobile Mastr II, low band 48mhz. I have the
control head, and the squelch control changes a voltage on the plug in panel test point, but the receiver stays un squelched. I am assuming that an RF squelch was disabled if this unit was on a PL tone, is there a wire or jumper to disable the squelch? Ed N3SDO Ed Bathgate RMA Dept (724) 772-8785 pager (412) 649-6773 |
|
Re: Squelch on GE Mastr II
KF4TNP
you can purchase one or build your own take a look at the NHRC web page
toggle quoted message
Show quoted text
under master II info Ed Bathgate RMA Repair Dept x8785 wrote: From: "Ed Bathgate, RMA Repair Dept x8785" <ed@...> |
|
Re: Squelch on GE Mastr II
mch
If you mean a squelch operated relay, it was an option on the base
toggle quoted message
Show quoted text
units. You can hear that relay trip hundreds of feet away from the unit. If you mean an internal (to the drawer unit) squelch, I think there may have been one, but it is really easy to build - just use a 10K pot with the ends tied to Vol-SQ hi and low respectively, and the center tied to the point marked Squelch Arm. There is a company that sells plug in boards for the M-II mobile (or base, I guess) that has both the squelch and audio pots mounted. See: I haven't used that module myself. I prefer multi-turn pots in the squelch circuit for additional control (accuracy). Joe, KR3P (also near the 'Burgh) Ed Bathgate, RMA Repair Dept x8785 wrote:
|
|
Down Time
Kevin K. Custer W3KKC
All subscribers,
Please be advised of the scheduled down time tonight. Kevin Custer W3KKC List Owner From: ONElist Tech Support Hello, The ONElist system will be down for scheduled maintenance this evening, Monday March 22, 1999. We will be off-line from 8pm to 10pm Pacific Time while we upgrade the system. That's 11pm to 1 am Eastern Time tonight. The ONElist Team |
|
Re: Hamtronics, and diverging....
that youI was going to purchase some Hamtronics equipment, then I saw what you wrote I use a Hamtronics R-220 receiver here on my 224.66Mhz repeater and itcan point me to so I can read about the stuff? works OK. But, just OK, nothing special. You also have to remember that it is located here at my house and does not have to compete with much other interference or overload. I bought my R-220 used about 10 years ago. At that time, 220 equipment was hard to come by and some of the commercial 220 conversions were not developed yet (or, not publicized as we can now do on the Internet). My choice now would be to convert a commercial piece of gear. Or, buy one already converted if you are weak at heart to delve into the circuitry. If you do decide to do the conversion and are new at it, I suggest you buy two radios. One to use for spare parts in the future. They are usually not very expensive. About the only place I feel Hamtronics has a place is possibly on 222Mhz. And, that's only if you don't want to do some of the semi-difficult mods to a piece of commercial gear. You will have a "fair" repeater that will work OK at your house. Anything more than those expectations and you will probably be disappointed. I have a lot of other Hamtronics stuff laying around here. But, it's old controller stuff. Before the days of cheap microprocessor controllers, Hamtronics was the easiest way to go to build controllers, phone patches, etc. But. those days are long gone. I don't for see a long future for Hamtronics, unfortunately. 73, Joe K1IKE |
|
Re: A Challenge.. / and another with a Mitrek
Joe Orrico WB6HRO
--
One more quick thing on a Mitrek. I have one on 440 I duplexed that is deaf as a stump until the TX comes up. Then, the sensitivity is great! As soon as the tail drops, it goes back to being deaf. Here's the kicker: it ONLY does it when connected to the duplexer. It works flawless if I connect the RX to an IFR to test the sensitivity. Deaf in this case is 'you have to find the right spot to key it with the HT on-site!' Sooo... any ideas out there??? Joe M. Sounds the the diode that must be removed to keep the voltage on the rx is not correct, would suspect that rx voltage is not right during normal rx function. We have been using about 10 Mitreks for link radios on our 220 system. Joe WB6HRO |
|
Re: Repeater-builder: Why?
Theodore M Leonard
Hi Chuk
toggle quoted message
Show quoted text
As you can see from the date,I am behind in my e-mail but I agree. best 73 Ted Chukgleasn@... wrote: From: Chukgleasn@... |
|
Re: A Challenge..
Joe Orrico WB6HRO
From: Chukgleasn@...
OK, everyone, where are the real RF Hackers? Here's the challenge: Develop some new ways to build 220MHz repeaters. Well Chuk there are several things that don't make alot of sense. First if I can buy a G.E. Master II or MVP for $20-30 and mod it for 220, my only challenge is to build a 10 - 15 watt PA. I have used the 220 brick from RF Parts and didn't use a circuit board, just a solder type terminal strip and UT-141 hardline to and from the terminal strip. So with the brick and the xtals you have about $100 in it. Newer radios cost alot more and where is the gain in perfromance? My 2 cents worth anyway. We have about 6 220 MVP's at high density sites in the L.A. Basin. de Joe Orrico WB6HRO |
|
Re: A Challenge.. / and another with a Mitrek
mch
Chukgleasn@... wrote:
I believe that would be the Delta, Delta-S, then Delta-SX (those are respectively crystal controlled, synthesized and wideband synthesized units) The -S would obviously be a better choice than the -SX for repeater use. BUT, if I recall correctly, virtually anything after the Micor/M-II era is rated at a poor duty cycle. (Except for the continuous duty repeaters, of course, that are still >$1K) As far as non-repeater use, I saw (@ Dayton a few years ago) someone with a 220 MHz GE MPA or MPD - I forget which. Anyway, I asked him how hard it was to convert, and he said a conversion would be very difficult. I mentioned that he seemed to have done it, and was told that it was produced that way from scratch. It seems he had the fortune of working at Lynchburg. (GE HQ if you don't know that) The radio was a prototype of a model that 'never would make production'. Lucky duck... Now, as for the comment about using newer /\/\ and GE/EGE radios for synthesized remote bases, I've heard a lot of people saying how it could be done with Syntors and such, but nobody seems to have the time to do it. :(( A Rangr or Maxtrac or Maratrac would make a kick-butt remote base! 8] All it takes is someone to capture and analyze a programming dump to the radio. The stored files (at least for the GEs) are simple hex conversions. If the dump is a pure dump of the file, that should be easy. /\/\ on the other hand has to confirm the model, S/N or what have you before dumping the data. We need a unit like the one GLB made that synthesized Micors - only processor based. It's probably infringing on some copyright, I suppose... (sigh) One more quick thing on a Mitrek. I have one on 440 I duplexed that is deaf as a stump until the TX comes up. Then, the sensitivity is great! As soon as the tail drops, it goes back to being deaf. Here's the kicker: it ONLY does it when connected to the duplexer. It works flawless if I connect the RX to an IFR to test the sensitivity. Deaf in this case is 'you have to find the right spot to key it with the HT on-site!' Sooo... any ideas out there??? Joe M. |
|
Re: Hamtronics, and diverging....
Kevin K. Custer W3KKC
Chukgleasn@... wrote:
From: Chukgleasn@...For my unsolicited opinion on Hamtronics, Go here Kevin |
|
Re: A Challenge..
Kevin K. Custer W3KKC
Jon Pearl W4ABC wrote:
I have to agree with Jon, When Motorola designed and built the Micor, they employed the best engineers that money could buy. This radio was developed as a part of Motorola's commitment to Americas Space Program. Money was not an object. I have peckered around with a lot of equipment, both older and new. The Micor line will either hold it's own or simply blow away the newer technology. I had recently had a chance to do some work on a newer Motorola MSF line repeater, their newer synthesized stuff. The Micor's specs, (over 30 years older in technology) simply blows away the receiver sensitivity. Why? The Micor was intended to work on a very narrow band from where it is tuned. Performance drops rapidly from this tuned point. In today's world where we require one radio to tune from DC to light, there is certainly a need for synthesized, processor tuned radios, but for a repeater where the frequency don't qsy often, the old slug tuned rigs cannot be beat. They are more sensitive, more selective, less susceptible to intermod, the squelch works better, I could go on and on. Lets face it, there has not really been any technology advances that make a 2 meter or 220 radio receive any better today than 20 years ago. The development in GaAs fet's only show performance enhancements from about 400 megs and above. Since the Micor and Mastr II radios are plentiful on the used market, we are now able to get first class radio technology for little to nothing. Just because this technology is old... it is not outdated. Kevin |
|
Re: A Challenge..
Jon Pearl W4ABC
toggle quoted message
Show quoted text
-----Original Message-----
From: Chukgleasn@... <Chukgleasn@...> To: Repeater-builder@... <Repeater-builder@...>; Repeaters@... <Repeaters@...> Date: Sunday, March 21, 1999 6:06 PM Subject: [Repeater-builder] A Challenge.. From: Chukgleasn@...Parts, then the PC board is $15. (I know, I'm starting to sound like the ham whofor the connectors! Guilty as charged!!!)How about it? The Mitrek has no "pork shop" (circulator);is a single board design; has fewer components. The "Micor" may well have been Motorolover's last "hurrah." The radio was expensive and probably over built for the times. Long ago when the Japanese started kicking our collective asses, Motorolover had to make some tough decisions. The answer came in the form of radios like the Mitrek and beyond. Makes a good remote base or linking radio, but there are so many other designs (READ Micor) out there more suitable for repeater service, why bother with looking for something different for the sake of something different? Later radios, Prom and RSS programmable's are neat, but the added expense involved for the sake of building up a single channel repeater can't be justified in my mind. Now if you had plans for a frequency/PL agile remote base, then something of this flavor, might just be your cup of tea. Jon Pearl W4ABC _________________________________________________________ "The people will not understand the importance of the Second Amendment until it is too late." -- Thomas Jefferson What's the next newer GE model? Come on, guys, let's get with it!!until someone posts " I woulda done it this way with a Fahrvergnugen F16 mobile, |
|
Re: Hamtronics, and diverging....
This was posted to me privately, and I thought after I started my reply I
would send it on to the list...... -============================= Hello: I was going to purchase some Hamtronics equipment, then I saw what you wrote about it. What is your opinion on the equipment? Are there negative write ups that you can point me to so I can read about the stuff? I have not heard much negative about the equipment, but then I might have not talked to the right people. Thank You D.L. Hogdon ====================================== Well, I've never had the joy of doing anything Hamtronics. Looked at them longingly before I got into the professional two-way field, as a cheap way to put up a repeater. Lots of people in the listserver or other places will laugh at them tho. One in particular is Chris Boone, WB5ITT. He'll recommend a converted two-way radio in a heartbeat. Then again, he's been doing this stuff since, it seems, Christ was a corporal... I also don't know how far back the onelist archives go - if they're significant size, you might look in there. Otherwise, email Chris - he posts to the various reflectors often enough. I guess now that I've been thinking about it while writing this reply, I might sum it up like this: 1) Hamtronics equipment probably costs as much as or more than 'salvaged' two-way. And salvaged two-way you have to find a place to salvage from and get service literature, etc. A job in itself, that Hamtronics, et al. lets you take care of by just opening your wallet to them. You do get the satisfaction of building it yourself. 2) The designs are probably a little long in the tooth - on the old side, not much in the way of new or uniqueness. On the other hand, that might mean stable< ; why mess with a thing that works?3) Any number of other reasons that people on the list might post. Hey! How about FAQ re. buy/build decisions, etc.? I don't want to start flame wars; this is similar to anybody's fascination with Chevy/Ford/Dodge/etc. Some just comes down to personal preference; "De gustibus nil est disputandum" (apologies to all Latin-language lovers for the spelling!) "There is no arguing about taste" Everybody put some thought into it. Everytime a new person comes on with a question about "How do I .." and "Which is better, General Eccentric or Motherola or ...?" this has to be done again. Me, I'd offer more opinions, but I'm still just a young pup..... Chuk Gleason |
|
A Challenge..
OK, everyone, where are the real RF Hackers?
Here's the challenge: Develop some new ways to build 220MHz repeaters. Here's why: Everyone has the GE ExecII and Micor VHF mobile mods all over the net. Can hardly get away from them. And I know there are strong opinions about Hamtronics, Spectrum, etc. Won't say which way they're strong, just that they're strong opinions. Besides, the Micor VHF PA, in words similar to what's written in the mod files, sucks wind at 220 and you have to run a Toshiba power module. Just the module is about $60.00 American from RF Parts, then the PC board is $15. (I know, I'm starting to sound like the ham who gets 7/8 inch hardline at 5% of cost then gripes about paying full price for the connectors! Guilty as charged!!!) How about some newer equipment? Say, Mitrek VHF. What's the next newer GE model? Come on, guys, let's get with it!! Anybody who comes up with an easy, elegant, way to do this with 'newer' equipment (how about hacking Motherola Maxtracs?) will win the praise and accolades of the other members of this list. For at least 35 minutes, until someone posts " I woulda done it this way with a Fahrvergnugen F16 mobile, this way....(Ya big dummy!!!! Why didn't ya think of that!!!!) : ) )" Chuk Gleason kb4mdz |
to navigate to use esc to dismiss