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#1
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I have a wireless receiver that seems to have a dead crystal in the
VCO. I called Nady who makes the unit and they want $15 + $10 shipping. This seems kind of high especially on the shipping front. It seems that the ham supply places only have ~30MHz as the highest. Anyone might be able suggest a source? |
#2
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#3
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Just pony up the money and be done with it....
Seems like a fair price... generic crystals are cheaper but you want accuracy and stability. http://www.icmfg.com/crystalfaqs.html http://www.bomarcrystal.com/ Rgds: Eric "Dave Runton" wrote in message om... I have a wireless receiver that seems to have a dead crystal in the VCO. I called Nady who makes the unit and they want $15 + $10 shipping. This seems kind of high especially on the shipping front. It seems that the ham supply places only have ~30MHz as the highest. Anyone might be able suggest a source? |
#4
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Dave Runton wrote:
I have a wireless receiver that seems to have a dead crystal in the VCO. I called Nady who makes the unit and they want $15 + $10 shipping. This seems kind of high especially on the shipping front. It seems that the ham supply places only have ~30MHz as the highest. Anyone might be able suggest a source? That's actually a pretty good price. The ham guys, like ICM and JAN Crystals will probably be in the same price range, but you will need to know the loading and what overtone the crystal operates at. VHF crystals are no problem for any of the guys, because they are basically lower frequency crystals that are cut to operate at harmonics. The cheapest crystal source I know of is QMX Crystals in El Paso. Six bucks each for VHF land/mobile crystals. 915-533-4453. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#6
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Dave Runton wrote:
I have a wireless receiver that seems to have a dead crystal in the VCO. I called Nady who makes the unit and they want $15 + $10 shipping. This seems kind of high especially on the shipping front. It seems that the ham supply places only have ~30MHz as the highest. Anyone might be able suggest a source? How much ****ing around are you prepared to do to save a few bux on $25, and maybe end up with the wrong thing ? geoff |
#7
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Paul Rubin wrote in message ...
(Dave Runton) writes: I have a wireless receiver that seems to have a dead crystal in the VCO. I called Nady who makes the unit and they want $15 + $10 shipping. This seems kind of high especially on the shipping front. It seems that the ham supply places only have ~30MHz as the highest. Anyone might be able suggest a source? Find out what the actual frequency of the crystal is. There's probably a frequency multiplier inside the receiver, like 18x or something. So a receive freq of 209.15 mhz would need a 23.38 mhz crystal. A 209.15 mhz xtal would have to be extremely tiny and I don't think I've heard of such a thing. Also a crystal for a receiver will have an offset for the IF. If the IF is 10.7 MHz then the LO will be 10.7 MHz offset from the input frequency. and the crystal will be an integer sub multiple of the LO. This is all assumming we're talking about a fixed freq unit and not a PLL. I agree with the others, $25 is a pretty good deal to get the EXACTLY correct crystal from the manufat. There are a lot more varibales for crystal beside frequwncy such a series or parallel mode and loading etc. You may be able to save $15 but it may take you on an adventure. Mark |
#8
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After some research I agree that 209MHz is probably not the crystal
frequency - it seems high - but that's the way it's marked.... Since the transmitter works, I took a look at it on the spectrum analyzer. Nothing else anywhere near the right level except down at 17.43MHz - so that works out to a 12x multiplier. The schematic doesn't really seem to have a multiplier in there but I should probably go through my ARRL handbook again ![]() The receiver still works even though the VCO is dead. I guess that all of the filters are just tuned up for the right frequency and there is enough energy to result in a demod-ed signal. But that's why the range sucks. It's such an old unit, I hate to throw a lot of $$$ just to have something to use for wireless around the house/studio. A whole receiver sells on ebay for $15 - just not the right frequency (doh!) I found some 17.47MHz crystals at digikey for $1 each. I'm just going to replace both sides and tweek the inductors for the slight change in frequency. It's worth a shot. Thanks for the inputs - as a ham - I am cheap! (wonder which came first) Too bad ebay has taken a lot of the fun out of hamfests. You just can't haggle with a guy who has prinouts of the latest closing prices from ebay on what he is selling. Dave - KD4FOE |
#9
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#10
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Your digikey crystals will be an interesting learning experience..... they
are most likely made for computer clocks..... where accuracy and temperature stability are not important.... thus their cheap price. The real ones not only would be matched to the drive level and load capacitance... but also might be matched for the temperature compensation.... Also if this is a receiver there will be an offset for the i.f. frequency as well as the multiplier.... If there is a vco in the circuit their is likely a Phase Lock Loop PLL multiplier.... and possibly a divider as well. In the end it might be an good learning experience, but you are not saving any money if you are wanting a useable microphone as an end result. Regards: Eric "Dave Runton" wrote in message om... After some research I agree that 209MHz is probably not the crystal frequency - it seems high - but that's the way it's marked.... Since the transmitter works, I took a look at it on the spectrum analyzer. Nothing else anywhere near the right level except down at 17.43MHz - so that works out to a 12x multiplier. The schematic doesn't really seem to have a multiplier in there but I should probably go through my ARRL handbook again ![]() The receiver still works even though the VCO is dead. I guess that all of the filters are just tuned up for the right frequency and there is enough energy to result in a demod-ed signal. But that's why the range sucks. It's such an old unit, I hate to throw a lot of $$$ just to have something to use for wireless around the house/studio. A whole receiver sells on ebay for $15 - just not the right frequency (doh!) I found some 17.47MHz crystals at digikey for $1 each. I'm just going to replace both sides and tweek the inductors for the slight change in frequency. It's worth a shot. Thanks for the inputs - as a ham - I am cheap! (wonder which came first) Too bad ebay has taken a lot of the fun out of hamfests. You just can't haggle with a guy who has prinouts of the latest closing prices from ebay on what he is selling. Dave - KD4FOE |
#11
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#13
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Lines: 37
Message-ID: X-Trace: npbhgpngjbkmjfegdbdpiflmbcekedmfhojhikkbagflhcboke knmdmdihmpiligpeiphjjefhhdbmabfejkniobkbfmcgpbibpi cobmcbhlkkaajbaohfbofmmmkjljfohgmnbjoeomcghhaoaggf blacphkafe NNTP-Posting-Date: Sat, 03 Apr 2004 21:15:22 EST Date: Sun, 04 Apr 2004 02:15:22 GMT Xref: number1.nntp.ash.giganews.com rec.audio.pro:1058128 On 2004-04-03 said: Too bad ebay has taken a lot of the fun out of hamfests. Boy, I'll say. I don't know how much overpriced junk I've seen that I might be able to use. When I make a more reasonable offer, the usual answer is "I'll just take it home and sell it for that or more on eBay." Amen brother! A year ago I was at the Baton ROuge La. hamfest and a lady had an old Heathkit hw100 transceiver. dUring my college days there was one at the college club station and I spent many enjoyable hours operating that rig. I knew I'd probably have to go through the thing changing out electrolytics and other goodies that were going south as her dad had been in a nursing home for a couple of years and hadn't used the rig. OF course all of his newer stuff was gone and she had some of his old hollow state stuff including three or four complete Heathkit stations. SHe didn't have the speaker with this one, just the transceiver and the power supply. TO make a long one short I offered her $100, she wanted $150. THis was her basic response. SHE must've got her $150 or better on eBay but from waht I saw looking around the innards of that radio it was worth $100 to me and not $150. Richard Webb Electric Spider Productions REplace anything before the @ symbol with elspider for real email -- "So she said it was either her or ham radio....OVER" |
#14
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Message-ID: X-Trace: ldjgbllpbapjglppdbdpiflmbcekedmfhojhikkbagflhcbohe ablmgfdjcnedhnnfmdnanoojkjibjdinibpkbmekgomiddibpi cobmcbhlkkaajbaohfbofmmmkjljhoibdmdanoonmemjkcnngd niofceagjf NNTP-Posting-Date: Sat, 03 Apr 2004 22:12:25 EST Date: Sun, 04 Apr 2004 03:12:25 GMT Xref: number1.nntp.ash.giganews.com rec.audio.pro:1058144 Paul wrote: Amen brother! A year ago I was at the Baton ROuge La. hamfest and a lady had an old Heathkit hw100 transceiver.... SHE must've got her $150 or better on eBay but from waht I saw looking around the innards of that radio it was worth $100 to me and not $150. That's a good point about Heathkits. You never know how good a job whoever assembled them did, unless you look inside. So buying one on ebay is sort of asking for it. But man, those were nice rigs back in those days. It's really cool to be able to get something like that now even for $150. You can even get something like a TS520 for not that much more. Anything of the sort would have cost several times more back in those days. ROger that. ONe thing I like about those or the Kenwood 520 is the 6146 finals instead of them TV sweep tubes. THe 6146 was a lot more rubst imho. This one looked like it was painstakingly put together, just old and knew I'd probably have to go through it, might as well shotgun all the caps in the power supply etc. THat's why to me for a nostalgia trip it was worth $100 but not $150. WOuld have been glad to put in the work on the bench to pull out the old green monster now and then to put on the air but not for $150. For $100 it took me down memory lane. I also cut myself off at $100 as I had gas to buy for the trip back to NEw Orleans and dinner yet. Luckily the xyl was along and kept me from meeting her demanded price. I might have done, but I'd already bought myself a new Heil microphone and the xyl a new two meter rig for the van. I had a HEath sb303 receiver at one time, many hoappy hours spent with it. I bought it after I left a Hamarlund hq180 in a pawn shop. That one really depressed me too. NOw there was a receiver!!! SOunded great listening to am or sw broadcasts and was a darned good receiver for sideband work too. IT would eat the receiver in the Icom 740 I have on the operating bench now for lunch! Richard Webb Electric Spider Productions REplace anything before the @ symbol with elspider for real email -- |