RE: [Repeater-Builder] "Bend" an ICOM a little further
> I just got some Bomar crystals (Not my choice) for the clubs > UHF Micor. The TX was off 14 to 39 kHz, Had to add a 10pF cap > to get the trimmer in the center range. Strangely the RX was fine. That's probably not indicitive of Bomar making a bad rock; you almost always have to change out the cap behind the trimmer to center the tuning range if the original frequency was significantly different than the new. Maybe you just got lucky on the RX element, but 9 times out of 10, I've had to change caps in Micor elements to get them to net, regardless of whether the crystal came from Bomar, ICM, or West Crystal. --- Jeff WN3A
Re: [Repeater-Builder] "Bend" an ICOM a little further
Les Smith died several years ago and the Company is no longer in business.
Les started making crystals at CTS in Streetsville Ontario and about 35 years
ago he started his
own company. I have lot's of his crystals here.
73 John VE3AMZ
Waterloo Ont. (Where the Blackberry was invented)
- Original Message -
From: Paul Plack
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, February 18, 2010 4:41 AM
Subject: Re: [Repeater-Builder] "Bend" an ICOM a little further
There used to be a great little company in the Toronto area called Lesmith
that did a nice job with crystals at prices below ICM's. They morphed a couple
times and changed names, but I think they're out of the crystal biz now. Anyone
have an update?
73,
Paul, AE4KR
- Original Message -
From: DCFluX
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, February 18, 2010 2:20 AM
Subject: Re: [Repeater-Builder] "Bend" an ICOM a little further
I just got some Bomar crystals (Not my choice) for the clubs UHF Micor. The
TX was off 14 to 39 kHz, Had to add a 10pF cap to get the trimmer in the center
range. Strangely the RX was fine.
Re: [Repeater-Builder] "Bend" an ICOM a little further
There used to be a great little company in the Toronto area called Lesmith that did a nice job with crystals at prices below ICM's. They morphed a couple times and changed names, but I think they're out of the crystal biz now. Anyone have an update? 73, Paul, AE4KR - Original Message - From: DCFluX To: Repeater-Builder@yahoogroups.com Sent: Thursday, February 18, 2010 2:20 AM Subject: Re: [Repeater-Builder] "Bend" an ICOM a little further I just got some Bomar crystals (Not my choice) for the clubs UHF Micor. The TX was off 14 to 39 kHz, Had to add a 10pF cap to get the trimmer in the center range. Strangely the RX was fine.
Re: [Repeater-Builder] "Bend" an ICOM a little further
Yeah, I could see that. He did not specify the crystal manufacture, plus the factory compensated the element to what crystal was originally in it. I just got some Bomar crystals (Not my choice) for the clubs UHF Micor. The TX was off 14 to 39 kHz, Had to add a 10pF cap to get the trimmer in the center range. Strangely the RX was fine. On Thu, Feb 18, 2010 at 2:01 AM, Paul Plack wrote: > > > DC, he was given a free crystal which turned out to be worth what he paid. > I never implied he was trying to rubber one cut for another channel, just > rubber one that was too far off frequency. > > 73, > Paul, AE4KR > >
Re: [Repeater-Builder] "Bend" an ICOM a little further
DC, he was given a free crystal which turned out to be worth what he paid. I never implied he was trying to rubber one cut for another channel, just rubber one that was too far off frequency. 73, Paul, AE4KR - Original Message - From: DCFluX To: Repeater-Builder@yahoogroups.com Sent: Wednesday, February 17, 2010 5:33 PM Subject: Re: [Repeater-Builder] "Bend" an ICOM a little further Seriously, some people need to read the original message before replying. The original complaint was running out of tunning range on the piston trimmer in the channel element while trying to net the crystal on frequency. Not rubbering the crystal to another channel or Nuclear warfare on an inactive club. Also I should mention that the receiver should be set by looking at the LO frequency on either a service monitor or a frequency counter of known precision, Tuning it until it sounds best is not the way to go. The LO frequency for the MASTR-II VHF will be either + or - 11.2 MHz from the receive frequency depending on the whether high side injection was specified when ordering the crystal. On Wed, Feb 17, 2010 at 3:52 PM, Paul Plack wrote: Forgive me if I'm going where no one wants to go, but isn't there a point in the decline of a club at which the nuclear option becomes the best choice? "Guys, the repeater's been a fun ride for 40 years, but we're down to three members, and no longer have enough in the treasury to keep the old girl running. The coordinator says there are people on the waiting list willing to spend the money to take care of a repeater. As I see it, we have two choices. I await your guidance. Sincerely..." 73, Paul, AE4KR
Re: [Repeater-Builder] "Bend" an ICOM a little further
> Doug wrote: > > Jared; > You need to warp 4khz not 400hz... If they were made up for 146.01 I would > assume that they can do that. >> >> Jared wrote: >> >> I just need the crystal to go up a hair more (400 Hz on the crystal freq). >> In Jared's defense, he did say "on the crystal frequency" He needs to go 3600 cycles higher on the channel, which relates to 400 cycles at the crystal because the LO multiplier in a VHF MASTR II receiver is 9 400 cycles (400 more than the present netting excursion, that is...) at the crystal frequency is going to be difficult without breaking the oscillator - IMHO. Kevin
Re: [Repeater-Builder] "Bend" an ICOM a little further
At 2/17/2010 16:33, you wrote: >Also I should mention that the receiver should be set by looking at the LO >frequency on either a service monitor or a frequency counter of known >precision, Tuning it until it sounds best is not the way to go. The LO >frequency for the MASTR-II VHF will be either + or - 11.2 MHz from the >receive frequency depending on the whether high side injection was >specified when ordering the crystal. My procedure for setting the RX freq.: 1. Tune LO chain (on MVPs & Exec IIs the 1st mult. stage will pull the oscillator freq. a little, so have to do this before netting the xtal). 2. Set LO freq. per above. 3. Tune front-end. 4. Move sig. gen. freq. +/- to see if RX is centered. 5. If RX is not centered, tune IF for best SINAD. 6. Repeat step 4. If RX is still not centered, move LO freq. to center IF. Bob NO6B
Re: [Repeater-Builder] "Bend" an ICOM a little further
Seriously, some people need to read the original message before replying. The original complaint was running out of tunning range on the piston trimmer in the channel element while trying to net the crystal on frequency. Not rubbering the crystal to another channel or Nuclear warfare on an inactive club. Also I should mention that the receiver should be set by looking at the LO frequency on either a service monitor or a frequency counter of known precision, Tuning it until it sounds best is not the way to go. The LO frequency for the MASTR-II VHF will be either + or - 11.2 MHz from the receive frequency depending on the whether high side injection was specified when ordering the crystal. On Wed, Feb 17, 2010 at 3:52 PM, Paul Plack wrote: > > > Forgive me if I'm going where no one wants to go, but isn't there a point > in the decline of a club at which the nuclear option becomes the best > choice? > > "Guys, the repeater's been a fun ride for 40 years, but we're down to three > members, and no longer have enough in the treasury to keep the old girl > running. The coordinator says there are people on the waiting list willing > to spend the money to take care of a repeater. As I see it, we have two > choices. I await your guidance. Sincerely..." > > 73, > Paul, AE4KR > > >
Re: [Repeater-Builder] "Bend" an ICOM a little further
Forgive me if I'm going where no one wants to go, but isn't there a point in the decline of a club at which the nuclear option becomes the best choice? "Guys, the repeater's been a fun ride for 40 years, but we're down to three members, and no longer have enough in the treasury to keep the old girl running. The coordinator says there are people on the waiting list willing to spend the money to take care of a repeater. As I see it, we have two choices. I await your guidance. Sincerely..." 73, Paul, AE4KR - Original Message - From: KE4ZDG To: Repeater-Builder@yahoogroups.com Sent: Tuesday, February 16, 2010 9:57 PM Subject: [Repeater-Builder] "Bend" an ICOM a little further Hey folks, I'm working on a GE Mastr II high band repeater. Someone gave me some crystals that were made up for 146.010 RX. I installed one in an EC ICOM and the best I can adjust for is 146.0064, which sounds really scratchy when I inject a >3k deviation signal on 146.010. When I tune the monitor down to 146.0064, the RX audio cleans right up. I've backed out the screw until there's no more threads left in the ICOM. Is there a capacitor I can change or add to give me a little more tuning range to the ICOM? I just need the crystal to go up a hair more (400 Hz on the crystal freq). I know I'm promoting cheapness by not buying another crystal, but the club doesn't have much money to spend. Thanks, Jared
Re: [Repeater-Builder] "Bend" an ICOM a little further
Jared; You need to warp 4khz not 400hz... If they were made up for 146.01 I would assume that they can do that. So now we need to look at why they are not... 10v reg power supply needs to be 10v +/- .1-.2v . The temp comp line to the EC needs to be driven to something by a 5ppm or eq channel element installed in the board, not necessarily even to be in band.. just to hold the comp line where it belongs... assuming it is not a comp line dc issue or a 10v reg dc issue, it is possible the xtal is from an exec II and while the xtal is the same freq, it is not the same cut... it may or may not tune in a Mastr II. On the other hand Mastr II xtals will in general function in both Exec II and Mastr II as a more precise cut. There is also a section of striplines at the top of the element that are actually there to fine trim the freq of the oscillator in the element. It is normally covered by the temp com circuit in an 2C and 5C. sometimes you can either repair or cut parts of that stripline area to move the center of the xtal. I would suspect that if the xtal is the correct one and it was assembled correctly.. it is more likely a DC issue to the comp line or 10v reg... The comp line needs to sit about 4.5 v, as I recall, for proper operation at room temp...Any 5C plugged in a spare element slot will drag it to the correct voltage... you can also measure it with a volt meter on any unused element pin spot that is not in use on that board... While in a mobile the comp line is common to the TX and RX.. in a station it is not.. you did not indicate what Mastr II you were working with.. Doug KD8B KE4ZDG wrote: > > Hey folks, > > I'm working on a GE Mastr II high band repeater. Someone gave me some > crystals that were made up for 146.010 RX. I installed one in an EC > ICOM and the best I can adjust for is 146.0064, which sounds really > scratchy when I inject a >3k deviation signal on 146.010. When I tune > the monitor down to 146.0064, the RX audio cleans right up. > > I've backed out the screw until there's no more threads left in the > ICOM. Is there a capacitor I can change or add to give me a little > more tuning range to the ICOM? I just need the crystal to go up a hair > more (400 Hz on the crystal freq). > > I know I'm promoting cheapness by not buying another crystal, but the > club doesn't have much money to spend. > > Thanks, > > Jared > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) <*> To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] "Bend" an ICOM a little further
Was the crystal that you got for 146.06RX made for a MASRTII radio, or something else? The cut can be different for different radio manufacturers. I have purchased only crystals for MASTRII and recrystalled my ICOMs with good luck. If I need to net them on frequency I use capacitors from the spare ICOMs that I have from the various mobile radios I have for spare parts. Lately, I have been sending the ICOMs back to ICM for recrystalling and temperature compensation. Yes it costs more, but I think it's worth it. Personally, I don't think that the club should have a repeater if they have no funding. You are supplying free labor, they should be able to spring for a few bucks. 73, Joe, K1ike > > On Feb 16, 2010, at 9:57 PM, KE4ZDG wrote: > > > Hey folks, > > > > I'm working on a GE Mastr II high band repeater. Someone gave me > some crystals that were made up for 146.010 RX. I installed one in an > EC ICOM and the best I can adjust for is 146.0064, which sounds really > scratchy when I inject a >3k deviation signal on 146.010. When I tune > the monitor down to 146.0064, the RX audio cleans right up. > > > > I've backed out the screw until there's no more threads left in the > ICOM. Is there a capacitor I can change or add to give me a little > more tuning range to the ICOM? I just need the crystal to go up a hair > more (400 Hz on the crystal freq). > > > > I know I'm promoting cheapness by not buying another crystal, but > the club doesn't have much money to spend. > > > > Thanks, > > > > Jared > > > > > > >
RE: [Repeater-Builder] "Bend" an ICOM a little further
You can do it but depending on the quality of the Parts you use it will drift. When You have it on the test bench and add caps Etc.. and it reads right on Freq , unless it is going to be within a few deg it will drift and When transmitting things will heat up and it will drift . I have done it on Scanners. etc But You are talking about a repeater with Someone's call on it and that may be at a remote site around other Commercial Emergency Equipment. I just had My Receive xtal for My 220 Micor repeater done at http://www.icmfg.com/Temp comp for about $50.00 The old one would drift gradually in a 3 Mo period and I would only notice this on Weak signals, I would adjust it back and it would drift. So I had the one made and I have never had a problem. You said the Club does not have much money, I have a 220 and 440 Repeater on the Air as a Hobby just to keep the old mind active , I do not have a Club or paying Members , Just a Old Disabled Vet on a fixed income, I don't know You a or your Club , But You tell me where and I will Donate $ 20.00 toward a New Xtal I mean all this in a good way you are a fellow ham Good Luck Don KA9QJG On Feb 16, 2010, at 9:57 PM, KE4ZDG wrote: > Hey folks, > > I'm working on a GE Mastr II high band repeater. Someone gave me some crystals that were made up for 146.010 RX. I installed one in an EC ICOM and the best I can adjust for is 146.0064, which sounds really scratchy when I inject a >3k deviation signal on 146.010. When I tune the monitor down to 146.0064, the RX audio cleans right up. > > I've backed out the screw until there's no more threads left in the ICOM. Is there a capacitor I can change or add to give me a little more tuning range to the ICOM? I just need the crystal to go up a hair more (400 Hz on the crystal freq). > > I know I'm promoting cheapness by not buying another crystal, but the club doesn't have much money to spend. > > Thanks, > > Jared
Re: [Repeater-Builder] "Bend" an ICOM a little further
I think you are referring to not being able to net the rocks to the correct frequency in your channel element. This is usually due to not enough or too much capacitance in the oscillator circuit. Good crystal manufacturers will supply the mid range temperature compensation capacitor with their crystal, others do not. Anyway this capacitor sits in parallel with the piston trimmer capacitor. You will have to experiment with values to get the right one, but the capacitor should have a NP0 or equivalent temperature coefficient. To find the right value set the trimmer approximately mid range and change values of the compensation cap, while the ICOM is as close to 26.5 degrees Centigrade as possible. If you are low in frequency, decrease the capacitance, if too high, increase it. On Tue, Feb 16, 2010 at 11:54 PM, Nate Duehr wrote: > > On Feb 16, 2010, at 9:57 PM, KE4ZDG wrote: > >> Hey folks, >> >> I'm working on a GE Mastr II high band repeater. Someone gave me some >> crystals that were made up for 146.010 RX. I installed one in an EC ICOM and >> the best I can adjust for is 146.0064, which sounds really scratchy when I >> inject a >3k deviation signal on 146.010. When I tune the monitor down to >> 146.0064, the RX audio cleans right up. >> >> I've backed out the screw until there's no more threads left in the ICOM. Is >> there a capacitor I can change or add to give me a little more tuning range >> to the ICOM? I just need the crystal to go up a hair more (400 Hz on the >> crystal freq). >> >> I know I'm promoting cheapness by not buying another crystal, but the club >> doesn't have much money to spend. >> >> Thanks, >> >> Jared
Re: [Repeater-Builder] "Bend" an ICOM a little further
On Feb 16, 2010, at 9:57 PM, KE4ZDG wrote: > Hey folks, > > I'm working on a GE Mastr II high band repeater. Someone gave me some > crystals that were made up for 146.010 RX. I installed one in an EC ICOM and > the best I can adjust for is 146.0064, which sounds really scratchy when I > inject a >3k deviation signal on 146.010. When I tune the monitor down to > 146.0064, the RX audio cleans right up. > > I've backed out the screw until there's no more threads left in the ICOM. Is > there a capacitor I can change or add to give me a little more tuning range > to the ICOM? I just need the crystal to go up a hair more (400 Hz on the > crystal freq). > > I know I'm promoting cheapness by not buying another crystal, but the club > doesn't have much money to spend. > > Thanks, > > Jared Just to comment on the "cheapness" part... you do realize you can re-rock an ICOM yourself? The crystal will run about $20-$25 last I checked from any of the reputable crystal houses. It won't be temperature-compensated or "burnt-in" and you could experience some frequency instability, but they usually work and settle down after anywhere from 6 months to a year. (Just visit the repeater every couple of months and check it.) I think I paid less than that once, even. Most folks here will recommend not being this "cheap" and having the whole ICOM sent in, full compensation, all that stuff... but for "non-critical" repeater stuff I've slapped ICM rocks in an ICOM and run with it. Especially for "test" crystals for use in the basement test lab, etc. $20-$25 is BEYOND cheap when the full price of a good, working, repeater system is factored against it. Of course, I think the full crystal and compensation are cheap, but I wouldn't put a repeater anywhere near a crap duplexer/antenna setup, having seen what good ones do for the system. Any pair of radios can be a repeater. The antenna system including duplexer, feedline, connectors, and antenna (plus lightning protection) makes it perform. You've also read the appropriate LBI manuals on the Repeater-Builder site and articles about EC ICOM's and how they require a 5C ICOM installed to drive their compensation voltage, right? Just checking. A lot of people will swear that you need 2C ICOMs for repeaters and then don't read the LBI's that a 5C ICOM will hold 2PPM within a very broad temperature range... and any 5C will compensate an EC. Only outside of that range in the chart in the LBI is the 2C even a necessity... so if the repeater lives in any kind of temperature-controlled environment... Anyway... my $0.02 and another buck will get you some Via instant coffee. :-) -- Nate Duehr, WY0X n...@natetech.com facebook.com/denverpilot twitter.com/denverpilot
[Repeater-Builder] "Bend" an ICOM a little further
Hey folks, I'm working on a GE Mastr II high band repeater. Someone gave me some crystals that were made up for 146.010 RX. I installed one in an EC ICOM and the best I can adjust for is 146.0064, which sounds really scratchy when I inject a >3k deviation signal on 146.010. When I tune the monitor down to 146.0064, the RX audio cleans right up. I've backed out the screw until there's no more threads left in the ICOM. Is there a capacitor I can change or add to give me a little more tuning range to the ICOM? I just need the crystal to go up a hair more (400 Hz on the crystal freq). I know I'm promoting cheapness by not buying another crystal, but the club doesn't have much money to spend. Thanks, Jared
