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3395 AM Filter
Looking to buy a 3395 AM filter as used in early tube Heathkit
receivers..any other suggestions on receiving AM with homebuilt filter system? TNX 73 Harold |
3395 AM Filter
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3395 AM Filter
"Michael Black" wrote in message
ample.net... For AM, there's probably a lot more possibilities. Pull some ceramic filters out of a CB set and cascade them, though those will be at 455KHz. All kinds of cordless phones, cb sets, some older cellphones, 49MHz superheterodyne walkie talkies and other consumer items use double conversion, with the first IF at 10.7MHz (and a wide ceramic filter there, the type you find in FM broadcast band receivers) and then a conversion to 455KHz, so they'd supply the needed crystal for the second conversion. If you're not stuck on a specific IF frequency, there's bound to be still lots of AM bandwidth crystal filters floating around, since after all relatively few were interested in good filters for AM, while SSB-width filters were very desired. Digi-Key stocks a number of ceramic and crystal filters that might be suitable for AM reception for less than $10 each, some for less than $2. They are willing to sell in small quantity and are one of the better distributors of electronic parts. Now one of the largest distributors, they got their start selling kits of parts for an integrated circuit keyer for hams. See: http://www.digikey.com/. -- 73, Dr. Barry L. Ornitz WA4VZQ [transpose digits to reply] |
3395 AM Filter
Dr. Barry L. Ornitz wrote:
"Michael Black" wrote in message xample.net... For AM, there's probably a lot more possibilities. Pull some ceramic filters out of a CB set and cascade them, though those will be at 455KHz. All kinds of cordless phones, cb sets, some older cellphones, 49MHz superheterodyne walkie talkies and other consumer items use double conversion, with the first IF at 10.7MHz (and a wide ceramic filter there, the type you find in FM broadcast band receivers) and then a conversion to 455KHz, so they'd supply the needed crystal for the second conversion. If you're not stuck on a specific IF frequency, there's bound to be still lots of AM bandwidth crystal filters floating around, since after all relatively few were interested in good filters for AM, while SSB-width filters were very desired. Digi-Key stocks a number of ceramic and crystal filters that might be suitable for AM reception for less than $10 each, some for less than $2. They are willing to sell in small quantity and are one of the better distributors of electronic parts. Now one of the largest distributors, they got their start selling kits of parts for an integrated circuit keyer for hams. See: http://www.digikey.com/. It _might_ be possible to shift the frequency of an existing ceramic filter up somewhat by judicious file and sandpaper work. I am not sure how much you can cut it before you screw the geometry up too much for it to work, though. If you need a weird frequency like this, though, I would first call ICM and see if they can make you something at a reasonable price. They have standard crystals for very cheap and I bet they won't charge much for filter crystals either. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
3395 AM Filter
On Tue, 10 Feb 2009, Tim Wescott wrote:
If it's the latter -- well, the same place may have what you want, or you may be out of luck (did the Heath rigs _have_ an AM selection? Mine certainly didn't), or you may have to mix to some other frequency (i.e. 455kHz), filter, and mix back. Note that my SB-201 didn't have an AM detector, either, so it may be more than just a filter that you need. If they kept the same IF frequency, and I know the SB line did use something in the 3MHz range, then there was at least one AM filter, for the shortwave band version of the SB series receiver, the SB-313 or something. There was a Heathkit receiver/transmitter set for AM about the time of their early SSB rigs, same sort of styling as the SSB rig of the time. The era of the Indian names. I don't know whether those used a high IF or used the traditional 455KHz, but if it was the former, they'd surely use the same 3MHz range scheme as the SSB equpment. Michael |
3395 AM Filter
On Tue, 10 Feb 2009 11:39:29 -0500, Michael Black wrote:
On Tue, 10 Feb 2009, Tim Wescott wrote: If it's the latter -- well, the same place may have what you want, or you may be out of luck (did the Heath rigs _have_ an AM selection? Mine certainly didn't), or you may have to mix to some other frequency (i.e. 455kHz), filter, and mix back. Note that my SB-201 didn't have an AM detector, either, so it may be more than just a filter that you need. If they kept the same IF frequency, and I know the SB line did use something in the 3MHz range, then there was at least one AM filter, for the shortwave band version of the SB series receiver, the SB-313 or something. There was a Heathkit receiver/transmitter set for AM about the time of their early SSB rigs, same sort of styling as the SSB rig of the time. The era of the Indian names. I don't know whether those used a high IF or used the traditional 455KHz, but if it was the former, they'd surely use the same 3MHz range scheme as the SSB equpment. Michael I believe there was a regular brand rig (Kenwood?) of about that era that also used the same mixing scheme, and had the same frequency fixed IF, if not all the same matching impedances. I can't really recall, though, other than I was thumbing through a replacement filter catalog and noticed it because I had the SB-201. -- http://www.wescottdesign.com |
3395 AM Filter
On Feb 9, 9:14*pm, " wrote:
Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? *TNX 73 *Harold Followup: I am looking for a 3395 KHZ. AM Filter for a Heathkit SB301 .The AM filter was offered as an Option . The SB 301 will not receive AM without the optional filter....It has AM detector and everything but the filter..I thought someone might have worked out a substitute for the Heath filter..like a high Q tuned IF can or whatever... TNX Harold |
3395 AM Filter
On Tue, 10 Feb 2009, Tim Wescott wrote:
I believe there was a regular brand rig (Kenwood?) of about that era that also used the same mixing scheme, and had the same frequency fixed IF, if not all the same matching impedances. I can't really recall, though, other than I was thumbing through a replacement filter catalog and noticed it because I had the SB-201. That sounds familiar, though I can't remember which brand it was either. I just did some searching, and I was thrown off by the mention of "early" in the first post. I was thinking of the Heathkit Commanche as a small receiver suitable for mobile operation, and it was used in tandem with the am Cheyenne transmitter. A check shows that receiver used a 3MHz IF. The Mohawk, which was a full blown receiver, used 1682KHz and then down to 50KHz, obviously not a standard combination in Heathkit receivers. The HR-20 Mobile SSB receiver used a 3MHz IF too. A quick search doesn't turn up what IF's the matching SSB transmitters were using, but I assume they too were 3MHz. So then Heathkit moved to 3395KHz, and that was pretty standard for a really long time. I think even the HW series of monoband SSB transceivers used the same frequency, though they used multiple crystals rather than prebuilt crystal filter. It's all relative, but I think of "early" as the pre-SB line, not the SB line itself. Heath kept the SB line going into the seventies, with cosmetic changes but the same basic design. Michael VE2BVW |
3395 AM Filter
Tim Wescott wrote:
I believe there was a regular brand rig (Kenwood?) of about that era that also used the same mixing scheme, and had the same frequency fixed IF, if not all the same matching impedances. I can't really recall, though, other than I was thumbing through a replacement filter catalog and noticed it because I had the SB-201. My fuzzy recollection says that 3395 shouldn't be difficult to find. A check of completed auctions on ebay didn't bear that out. I suppose it depends on how big of a hurry you're in :) -Bill |
3395 AM Filter
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3395 AM Filter
wrote in message ... On Feb 9, 9:14 pm, " wrote: Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? TNX 73 Harold Followup: I am looking for a 3395 KHZ. AM Filter for a Heathkit SB301 .The AM filter was offered as an Option . The SB 301 will not receive AM without the optional filter....It has AM detector and everything but the filter..I thought someone might have worked out a substitute for the Heath filter..like a high Q tuned IF can or whatever... TNX Harold I worked on a National NC-300 a few months ago. It had a conversion from a coil to a crystal at the second converter stage. About half way down the page: http://www.ppinyot.com/N/national/national.htm look for the "Second Converter modification at V3 6BE6" paragraph. Schematics and FNBs are on BAMA. The crystal used in the NC-300 is not at your frequency. But a crystal company should be able to make you one. I purchased Hammarlund specific crystals from http://www.icmfg.com/ The crystals were about 25 bucks each. AND the woman that answered the phone is not just a receptionist. She knew exactly which crystals I needed for the Hammarlund and what overtone and impedance!!! Not that she is a woman but she knew exactly what the vintage crystal replacement I needed! I hope this leads you some where. Paul P. |
3395 AM Filter
On Wed, 11 Feb 2009, Paul P wrote:
wrote in message ... On Feb 9, 9:14 pm, " wrote: Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? TNX 73 Harold Followup: I am looking for a 3395 KHZ. AM Filter for a Heathkit SB301 .The AM filter was offered as an Option . The SB 301 will not receive AM without the optional filter....It has AM detector and everything but the filter..I thought someone might have worked out a substitute for the Heath filter..like a high Q tuned IF can or whatever... TNX Harold I worked on a National NC-300 a few months ago. It had a conversion from a coil to a crystal at the second converter stage. About half way down the page: http://www.ppinyot.com/N/national/national.htm look for the "Second Converter modification at V3 6BE6" paragraph. Schematics and FNBs are on BAMA. The crystal used in the NC-300 is not at your frequency. But a crystal company should be able to make you one. I purchased Hammarlund specific crystals from http://www.icmfg.com/ The crystals were about 25 bucks each. AND the woman that answered the phone is not just a receptionist. She knew exactly which crystals I needed for the Hammarlund and what overtone and impedance!!! Not that she is a woman but she knew exactly what the vintage crystal replacement I needed! Who knows, but likely they have it on computer. The old crystal manufacturers tended to keep such information around, and certainly once they had the information because someone had sent it to them to get a needed crystal ground, they'd surely have kept it. So after a while, they could just look up the information. If they bothered to computerize it, then all they'd have to do is type in some search terms, and out would pop the needed information. That wouldn't require someone who knew all the details by heart. Michael VE2BVW |
3395 AM Filter
On Tue, 10 Feb 2009 22:47:06 -0500, Michael Black wrote:
On Wed, 11 Feb 2009, Paul P wrote: wrote in message news:722c01b0- ... On Feb 9, 9:14 pm, " wrote: Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? TNX 73 Harold Followup: I am looking for a 3395 KHZ. AM Filter for a Heathkit SB301 .The AM filter was offered as an Option . The SB 301 will not receive AM without the optional filter....It has AM detector and everything but the filter..I thought someone might have worked out a substitute for the Heath filter..like a high Q tuned IF can or whatever... TNX Harold I worked on a National NC-300 a few months ago. It had a conversion from a coil to a crystal at the second converter stage. About half way down the page: http://www.ppinyot.com/N/national/national.htm look for the "Second Converter modification at V3 6BE6" paragraph. Schematics and FNBs are on BAMA. The crystal used in the NC-300 is not at your frequency. But a crystal company should be able to make you one. I purchased Hammarlund specific crystals from http://www.icmfg.com/ The crystals were about 25 bucks each. AND the woman that answered the phone is not just a receptionist. She knew exactly which crystals I needed for the Hammarlund and what overtone and impedance!!! Not that she is a woman but she knew exactly what the vintage crystal replacement I needed! Who knows, but likely they have it on computer. The old crystal manufacturers tended to keep such information around, and certainly once they had the information because someone had sent it to them to get a needed crystal ground, they'd surely have kept it. So after a while, they could just look up the information. If they bothered to computerize it, then all they'd have to do is type in some search terms, and out would pop the needed information. That wouldn't require someone who knew all the details by heart. Michael VE2BVW But, in such a situation having someone willing and able to properly fondle the keyboard, then cheerfully tell you what you need to know, is still better than a snide gum-chewing receptionist! I try not to undervalue order-takers and such. Given how much value they can add when they're on the ball (and how much they can screw up when they're not), one cannot dismiss them as "just" anything. -- http://www.wescottdesign.com |
3395 AM Filter
Tim Wescott wrote:
But, in such a situation having someone willing and able to properly fondle the keyboard, then cheerfully tell you what you need to know, is still better than a snide gum-chewing receptionist! I try not to undervalue order-takers and such. Given how much value they can add when they're on the ball (and how much they can screw up when they're not), one cannot dismiss them as "just" anything. Well, we 'hams' often are not the easiest customers to deal with because we 'know' more than the gal on the other end of the phone :) That said, I not so long ago ordered some xtals from JAN and mentioned my old Harvey-Wells TBS-50 and the gal lit up like she knew what I was talking about. JAN has my business ever since. -Bill |
3395 AM Filter
In article ,
Bill M wrote: Tim Wescott wrote: But, in such a situation having someone willing and able to properly fondle the keyboard, then cheerfully tell you what you need to know, is still better than a snide gum-chewing receptionist! I try not to undervalue order-takers and such. Given how much value they can add when they're on the ball (and how much they can screw up when they're not), one cannot dismiss them as "just" anything. Well, we 'hams' often are not the easiest customers to deal with because we 'know' more than the gal on the other end of the phone :) That said, I not so long ago ordered some xtals from JAN and mentioned my old Harvey-Wells TBS-50 and the gal lit up like she knew what I was talking about. JAN has my business ever since. ICM and JAN are both this way and they are both absolute joys to deal with. They know what you want, they know how to make it, and they know what a fair price is. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
3395 AM Filter
wrote:
Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? TNX 73 Harold For crystals, try MH Electronics, Rancho Cucamonga, CA. Been using them on MIL rigs, many with some pretty high currents. So far, 100%. They say they use large blank crystals for their HC-6-style units, not those sub-minis that will fail if you look at them crooked. 73 de K3HVG -- Posted Via Newsfeeds.com Premium Usenet Newsgroup Service ---------------------------------------------------------- http://www.Newsfeeds.com |
3395 AM Filter
"Scott Dorsey" wrote in message ... ICM and JAN are both this way and they are both absolute joys to deal with. They know what you want, they know how to make it, and they know what a fair price is. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." Jan, ICM, and Sentry... I must have spend hundreds of bucks when I was a young ham on FM crystals for the latest Motorola or RCA twoway castoff I was converting for one of the VHF or UHF ham bands! I remember when ICM had cheap EX grade crystals for experimenters, and when JAN would mail you list of cheap surplus crystals they had on hand. Pete |
3395 AM Filter
On Feb 9, 10:14*pm, " wrote:
Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? *TNX 73 *Harold Heathkit AM filters show up on eBay and at hamfests from time to time. There are two types, big and little. They work in different radio's. The big filters are from the first SB radios. SB-300 used the big filter, the SB-301 and SB-303 used the small filter. Within the types, there are two bandwidths available. 3.5 kHz and 5.0 kHz. The 3.5 was the optional filter for the SB ham band receivers like the SB-300, SB-301 and SB-303. The 5.0 was the STANDARD filter for the SB SWL receiver like the SB-310 and the SB-313. Expect to pay about $30 for a 3.5 and $100 for a 5.0 filter. The 3.5 is not "full frequency" and the 5.0 is more hi-fi. You can force fit either filter type in any SB receiver but look for the proper size and it will bolt in. good luck. |
3395 AM Filter
In article
, " wrote: Looking to buy a 3395 AM filter as used in early tube Heathkit receivers..any other suggestions on receiving AM with homebuilt filter system? TNX 73 Harold Harold- There was a thread a few weeks ago, about someone buying out Heath's remaining parts and manuals. I understand the company is still in business, just not selling kits. http://www.heathkit.com/ If you give them a call, they might tell you how to contact the person or company that bought their old parts. There may be a slim chance your filter is available. Fred K4DII |
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