Re: [time-nuts] Minicircuits 10% discount in December
On 27 Nov 2014 13:56, Jim Lux jim...@earthlink.net wrote: Time to stock up on those transformers, mixers, amplifiersgrin Throughout the month of December, all online orders of any quantity of any Mini-Circuits catalog model from our web store on minicircuits.com will receive a 10% *discount! I thought I would place my order online to get the discount, whereas I normally do by phone. I decided to order from the USA rather than the UK. MiniCircuits charged me $102 to ship twelve SMA terminations and ten N terminations by UPS. That is their shipping handling change. I could send the same bits from the UK to the USA for less than 50% of that and I don't have a UPS account. A UPS account holder would get a better rate. I can get free shipping in the UK if I spend more than some relatively small amount, but I pay a lot more for the parts. Minicircuits use an exchange rate of close to 1 USD = 1 GBP. I seem to be between a rock and a hard place - either pay a ridiculous exchange rate, or pay a ridiculous shipping handling cost. Dave, G8WRB. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Am 05.12.2014 um 10:29 schrieb Dr. David Kirkby (Kirkby Microwave Ltd): change rate of close to 1 USD = 1 GBP. I seem to be between a rock and a hard place - either pay a ridiculous exchange rate, or pay a ridiculous shipping handling cost. Dave, G8WRB. Try Digi-Key. Free shipping for orders €65. I have observed delivery times 36h to Germany. It may not be MiniCircuits but Pulse, Macom, Avago, Infineon, EPCOS, Sky, AD, Hittite... Prices are ok. England won't be much different than EU. Gerhard, dk4xp ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi On Dec 5, 2014, at 4:29 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: On 27 Nov 2014 13:56, Jim Lux jim...@earthlink.net wrote: Time to stock up on those transformers, mixers, amplifiersgrin Throughout the month of December, all online orders of any quantity of any Mini-Circuits catalog model from our web store on minicircuits.com will receive a 10% *discount! I thought I would place my order online to get the discount, whereas I normally do by phone. I decided to order from the USA rather than the UK. MiniCircuits charged me $102 to ship twelve SMA terminations and ten N terminations by UPS. That is their shipping handling change. I could send the same bits from the UK to the USA for less than 50% of that and I don't have a UPS account. A UPS account holder would get a better rate. Shipping across the atlantic has become silly expensive over the last decade. There are a *lot* of organizations that are behind the curve on figuring out how to do it cheaply. Bob I can get free shipping in the UK if I spend more than some relatively small amount, but I pay a lot more for the parts. Minicircuits use an exchange rate of close to 1 USD = 1 GBP. I seem to be between a rock and a hard place - either pay a ridiculous exchange rate, or pay a ridiculous shipping handling cost. Dave, G8WRB. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 5 Dec 2014 12:23, Bob Camp kb...@n1k.org wrote: Shipping across the atlantic has become silly expensive over the last decade. There are a *lot* of organizations that are behind the curve on figuring out how to do it cheaply. Bob I ship VNA calibration kits across the Atlantic almost every week - admittedly in the other direction. It doesn't cost me anything like what Minicircuits charge. I regularly buy thins sent via Fedex, UPS and DHL, and don't pay so much to ship what must be less than 2 kg - possibly less than 1 kg. I suspect that the handling part of the charge is the real problem. Dave. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 12/5/14, 4:50 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: On 5 Dec 2014 12:23, Bob Camp kb...@n1k.org wrote: Shipping across the atlantic has become silly expensive over the last decade. There are a *lot* of organizations that are behind the curve on figuring out how to do it cheaply. Bob I ship VNA calibration kits across the Atlantic almost every week - admittedly in the other direction. It doesn't cost me anything like what Minicircuits charge. I regularly buy thins sent via Fedex, UPS and DHL, and don't pay so much to ship what must be less than 2 kg - possibly less than 1 kg. I suspect that the handling part of the charge is the real problem. There's probably some peculiarity that makes it difficult for MiniCircuits. Maybe they have to jump through some export control hoops or there's some hazardous material declaration or some such; and they haven't figured out how to do it cheaply. It could be as simple as it's an outlier and a very manual process. You could send them a nice inquiry and ask.. It is odd, but not surprising. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Bob Camp wrote: Hi On Nov 28, 2014, at 8:48 PM, Dave M dgmin...@mediacombb.net wrote: Gerhard Hoffmann wrote: Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard Thanks Gerhard, but I can't get that link to work. It sends me to Google, which tells me that I need to enable Javascript. Javascript has been turned on and running on my system for years, but apparently, that link doesn't see it. The link animates a Google search for the part number. The first thing that comes up here is the standard Mini-Circuits spec sheet for the part. It’s got the usual S parameter data, but nothing on DC current. Bob Thanks for clearing that up, Bob. I have had the spec sheet for quite a while, but its only mention of DC current is the Max DC spec of 30ma, but no data describing the effects of it on the device's performance. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi On Nov 29, 2014, at 5:26 AM, Dave M dgmin...@mediacombb.net wrote: Bob Camp wrote: Hi On Nov 28, 2014, at 8:48 PM, Dave M dgmin...@mediacombb.net wrote: Gerhard Hoffmann wrote: Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard Thanks Gerhard, but I can't get that link to work. It sends me to Google, which tells me that I need to enable Javascript. Javascript has been turned on and running on my system for years, but apparently, that link doesn't see it. The link animates a Google search for the part number. The first thing that comes up here is the standard Mini-Circuits spec sheet for the part. It’s got the usual S parameter data, but nothing on DC current. Bob Thanks for clearing that up, Bob. I have had the spec sheet for quite a while, but its only mention of DC current is the Max DC spec of 30ma, but no data describing the effects of it on the device's performance. My past experience with Minicircuits is that they will not give you any data the “extends” the spec on a part. Simply put - if you are after 1 MHz data on a part that stops at 10, they are not likely to supply it. I guess the policy is in place so they don’t wind up with parts spec’d outside their normal range. I’d still give them a call, the policy may have changed, or it may not apply to current … Bob Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
you can try the following vendor (RF Elettronica): http://www.rf-microwave.com/en/shop.html They ship abroad and prices are rather good. _ Elio. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Rick, Thanks for the brief review of MiniCircuits stuff (I'm not connected with them in any way except as a customer). Since you've characterized some of their parts, perhaps you could help answer a question that someone else posted, and one that I would like to have answered as well. Have you measured the effects of DC current in the windings of an RF transformer, such as is seen if the transformer is in the collector circuit of an amplifier? If so, could you provide a generalization of the effects, such as changes in frequency response, losses, etc.? Many Thanks!, Dave M Richard (Rick) Karlquist wrote: On 11/27/2014 7:07 AM, Tim Shoppa wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE You need the tiny cores to get the performance of the MiniCircuits transformers. You just can't get the same bandwidth using macro sized binocular cores. Now, if you don't need a lot of bandwidth, then what you are saying could make sense. Another issue is stray capacitance. Considerably lower with a tiny core. I have spent many hours characterizing MiniCircuits transformers beyond the data sheet specs, and dissecting them to learn how they do it. They really do have a lot of rocket science in them. In terms of the engineering I am buying (especially in a one-off application) they are ridiculously cheap. And I say that as a fairly knowledgeable transformer designer in my own right. I do keep binocular cores around for higher power transformers, and for emergencies when I need a transformer yesterday. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/28/2014 10:08 AM, Dave M wrote: Rick, Thanks for the brief review of MiniCircuits stuff (I'm not connected with them in any way except as a customer). Since you've characterized some of their parts, perhaps you could help answer a question that someone else posted, and one that I would like to have answered as well. Have you measured the effects of DC current in the windings of an RF transformer, such as is seen if the transformer is in the collector circuit of an amplifier? If so, could you provide a generalization of the effects, such as changes in frequency response, losses, etc.? Many Thanks!, Dave M The very tiny cores on MiniCircuits transformers will start to saturate at hundreds of mA. The effect is that the magnetizing inductance drops, which matters more at low frequencies than high frequencies. I try to avoid feeding DC to an amplifier through a transformer winding. Instead I use a separate RF choke for that. However, it would probably work OK for, say, up to 25 mADC for a small signal transistor, but why take a chance. If you are using a DC feed through a transformer winding, be careful not to accidently short circuit it, causing the full available current from the power supply to flow through the transformer. This can actually magnetize the core and permanently damage it. Saturation via DC is much more deleterious than saturation via AC. It is easy to calculate the flux density using Ampere's law, which is one of the four Maxwell's equations. H = I/(2piR). Since R (radius) is in the denominator, cores saturate from the inside first before the whole core is saturated. Multiply H by mu, (as any time nut knows) to get B. If R is 1 mm, and I is 628 mA, then H = 10 ampere turns per meter. If mu-relative is 1000, then B = 4piX10^-7 X 1000 X 10 = 125 mT. That is a hefty 1250 Gauss. Some materials may be affected at 1/10 this flux density. Now a days, a lot of RF is differential, in which case you are free to feed DC through the output transformer without worrying about this issue. I worked for several companies where those 6 hole cylindrical chokes were ubiquitous. I specifically characterized those and established a maximum current rating of only 100 mA. Of course, many production designs exceeded this limit and worked anyway. I actually observed someone try to put 20A through one of these. The tantalum capacitors on the cold side of the bead actually exploded due to RF current. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi On Nov 28, 2014, at 2:27 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: On 11/28/2014 10:08 AM, Dave M wrote: Rick, Thanks for the brief review of MiniCircuits stuff (I'm not connected with them in any way except as a customer). Since you've characterized some of their parts, perhaps you could help answer a question that someone else posted, and one that I would like to have answered as well. Have you measured the effects of DC current in the windings of an RF transformer, such as is seen if the transformer is in the collector circuit of an amplifier? If so, could you provide a generalization of the effects, such as changes in frequency response, losses, etc.? Many Thanks!, Dave M The very tiny cores on MiniCircuits transformers will start to saturate at hundreds of mA. The effect is that the magnetizing inductance drops, which matters more at low frequencies than high frequencies. I try to avoid feeding DC to an amplifier through a transformer winding. Instead I use a separate RF choke for that. However, it would probably work OK for, say, up to 25 mADC for a small signal transistor, but why take a chance. If you are using a DC feed through a transformer winding, be careful not to accidently short circuit it, causing the full available current from the power supply to flow through the transformer. This can actually magnetize the core and permanently damage it. Saturation via DC is much more deleterious than saturation via AC. It is easy to calculate the flux density using Ampere's law, which is one of the four Maxwell's equations. H = I/(2piR). Since R (radius) is in the denominator, cores saturate from the inside first before the whole core is saturated. Multiply H by mu, (as any time nut knows) to get B. If R is 1 mm, and I is 628 mA, then H = 10 ampere turns per meter. If mu-relative is 1000, then B = 4piX10^-7 X 1000 X 10 = 125 mT. That is a hefty 1250 Gauss. Some materials may be affected at 1/10 this flux density. Now a days, a lot of RF is differential, in which case you are free to feed DC through the output transformer without worrying about this issue. I worked for several companies where those 6 hole cylindrical chokes were ubiquitous. I specifically characterized those and established a maximum current rating of only 100 mA. Of course, many production designs exceeded this limit and worked anyway. I actually observed someone try to put 20A through one of these. The tantalum capacitors on the cold side of the bead actually exploded due to RF current. If you do need to run substantial current through a choke core, the larger binocular cores with a half turn through them are a better choice. Still useless for 20A (or even 2A) though … Bob Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/28/2014 1:04 PM, Bob Camp wrote: If you do need to run substantial current through a choke core, the larger binocular cores with a half turn through them are a better choice. Still useless for 20A (or even 2A) though … Bob The binocular cores come in several hole sizes. All other things being equal, current handling capacity is directly proportional to hole size. One thing to watch out for with putting DC thru binocular cores happens in push pull RF power amplifiers. The output transformer is usually a binocular core on steroids, or its equivalent constructed with beads or sleeves, etc, threaded over a single turn made from brass tubes connected together at the end away from the transistors. In cheap (illegal) CB amplifiers, you will frequently see +13.6 VDC connected to the junction of the brass tubes, as if it were a center tap. It actually isn't a center tap in terms of core saturation, and the DC currents to the transistors are unmitigated in terms of magnetizing the core. Although the cores are larger, so are the currents, and these amplifiers just live with the degradation including the magnetization. This occurs because each core sees only a half-turn. If you replace the tubes with a 2 turn wire primary, then the problem goes away, but of course then the amplifier would never work as high as 27 MHz, which is does normally only by resonating stray PC board trace inductance with peaking capacitors on the transformer. This forms a two stage step up structure. If you improve the layout to get rid of the trace inductance, the amplifier no longer works! See Motorola AN-762. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
The very tiny cores on MiniCircuits transformers will start to saturate at hundreds of mA. The effect is that the magnetizing inductance drops, which matters more at low frequencies than high frequencies. I try to avoid feeding DC to an amplifier through a transformer winding. Instead I use a separate RF choke for that. However, it would probably work OK for, say, up to 25 mADC for a small signal transistor, but why take a chance. If you are using a DC feed through a transformer winding, be careful not to accidently short circuit it, causing the full available current from the power supply to flow through the transformer. This can actually magnetize the core and permanently damage it. Saturation via DC is much more deleterious than saturation via AC. It is easy to calculate the flux density using Ampere's law, which is one of the four Maxwell's equations. H = I/(2piR). Since R (radius) is in the denominator, cores saturate from the inside first before the whole core is saturated. Multiply H by mu, (as any time nut knows) to get B. If R is 1 mm, and I is 628 mA, then H = 10 ampere turns per meter. If mu-relative is 1000, then B = 4piX10^-7 X 1000 X 10 = 125 mT. That is a hefty 1250 Gauss. Some materials may be affected at 1/10 this flux density. Now a days, a lot of RF is differential, in which case you are free to feed DC through the output transformer without worrying about this issue. I worked for several companies where those 6 hole cylindrical chokes were ubiquitous. I specifically characterized those and established a maximum current rating of only 100 mA. Of course, many production designs exceeded this limit and worked anyway. I actually observed someone try to put 20A through one of these. The tantalum capacitors on the cold side of the bead actually exploded due to RF current. Rick Karlquist N6RK Thanks for the insight, Rick. You confirmed many of my own assumptions about RF transformers and cores. I hadn't thought about permanently magnetizing a core with excessive DC current, but it makes sense. Same theory applies to line frequency power transformers and inductors; if the core saturates, inductance takes a nose-dive and current goes wild. A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Cheers, Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Gerhard Hoffmann wrote: Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard Thanks Gerhard, but I can't get that link to work. It sends me to Google, which tells me that I need to enable Javascript. Javascript has been turned on and running on my system for years, but apparently, that link doesn't see it. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi On Nov 28, 2014, at 8:48 PM, Dave M dgmin...@mediacombb.net wrote: Gerhard Hoffmann wrote: Am 28.11.2014 um 23:42 schrieb Dave M: A couple weeks ago, I sent an email to the Minicircuits technical support folks in hopes of getting this, or similar, info about a couple of their transformer models (specifically, T1-1 and T4-1-KK81), but so far, I'm still waiting. Guess I should give them a call.. got great technical advice from them when I called for help some time ago. Try that: http://lmgtfy.com/?q=T1-1-KK81.pdf The first anwer looks like a hit. regards, Gerhard Thanks Gerhard, but I can't get that link to work. It sends me to Google, which tells me that I need to enable Javascript. Javascript has been turned on and running on my system for years, but apparently, that link doesn't see it. The link animates a Google search for the part number. The first thing that comes up here is the standard Mini-Circuits spec sheet for the part. It’s got the usual S parameter data, but nothing on DC current. Bob Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi What time (note the tie in to be on topic for the list :) will their retail location open on Thanksgiving? Spending quality time on the auction sites can yield some pretty substantial discounts on RF transformers. The search process is not simple due to the crazy range of part numbers. Once you have the transformer you get to decide how to handle coax grounds. In most cases the solution either creates a bunch of problems or it eliminates any benefit of transformer isolation. Bob Sent from my iPhone On Nov 27, 2014, at 7:55 AM, Jim Lux jim...@earthlink.net wrote: Time to stock up on those transformers, mixers, amplifiersgrin Throughout the month of December, all online orders of any quantity of any Mini-Circuits catalog model from our web store on minicircuits.com will receive a 10% *discount! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE On Thu, Nov 27, 2014 at 9:58 AM, Bob Camp kb...@n1k.org wrote: Hi What time (note the tie in to be on topic for the list :) will their retail location open on Thanksgiving? Spending quality time on the auction sites can yield some pretty substantial discounts on RF transformers. The search process is not simple due to the crazy range of part numbers. Once you have the transformer you get to decide how to handle coax grounds. In most cases the solution either creates a bunch of problems or it eliminates any benefit of transformer isolation. Bob Sent from my iPhone On Nov 27, 2014, at 7:55 AM, Jim Lux jim...@earthlink.net wrote: Time to stock up on those transformers, mixers, amplifiersgrin Throughout the month of December, all online orders of any quantity of any Mini-Circuits catalog model from our web store on minicircuits.com will receive a 10% *discount! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi I believe I made that point earlier. The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. I still go shopping for more as projects come up Bob Sent from my iPhone On Nov 27, 2014, at 9:07 AM, Tim Shoppa tsho...@gmail.com wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE On Thu, Nov 27, 2014 at 9:58 AM, Bob Camp kb...@n1k.org wrote: Hi What time (note the tie in to be on topic for the list :) will their retail location open on Thanksgiving? Spending quality time on the auction sites can yield some pretty substantial discounts on RF transformers. The search process is not simple due to the crazy range of part numbers. Once you have the transformer you get to decide how to handle coax grounds. In most cases the solution either creates a bunch of problems or it eliminates any benefit of transformer isolation. Bob Sent from my iPhone On Nov 27, 2014, at 7:55 AM, Jim Lux jim...@earthlink.net wrote: Time to stock up on those transformers, mixers, amplifiersgrin Throughout the month of December, all online orders of any quantity of any Mini-Circuits catalog model from our web store on minicircuits.com will receive a 10% *discount! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/27/14, 7:07 AM, Tim Shoppa wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? Probably depends on the frequency ranges and such. The commercial transformers are very small, and probably have more consistent properties. If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Sure.. it's a trade time for money situation. OTOH, most hobby tinkerers are not going to fabricate semiconductor devices like MMICs (although I'm sure there's a [semi-fab-nuts] list out there for folks who have a 3 wafer line in their garage). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp kb...@n1k.org wrote: The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. The mainline distributors (Allied, Newark, Mouser, etc.) have excellent selection of Fair-Rite and other cores. Admittedly to a neophyte the equivalence of Fair-Rite or Laird part numbers to an Amidon-style number may not be evident. Clifton labs has excellent webpages of examples and is also a good way to find the cores sizes and materials commonly stocked at the mainline distributors using the manufacturer's part number (often with cross-ref to Amidon style number as a strong hint!) Recently some here expressed concern that the mini-circuits part may saturate with medium DC currents. Of course if you are doing a SMT production run you don't want to use bigger cores than necessary and most of the mini-circuits parts tend to be physically very tiny to meet this market. But if you wind your own on bigger cores this is a non-issue. Tim N3QE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi At least last time I looked, the “easy to find” distributors had great selections of parts used for switching power supplies and EMI suppression. When you started to dig for the specialized parts for RF transformers and tuned filters, the stock was pretty thin to nonexistent. If you move from ferrite to powdered iron, the search process alway has been more difficult... Bob On Nov 27, 2014, at 11:09 AM, Tim Shoppa tsho...@gmail.com wrote: On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp kb...@n1k.org wrote: The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. The mainline distributors (Allied, Newark, Mouser, etc.) have excellent selection of Fair-Rite and other cores. Admittedly to a neophyte the equivalence of Fair-Rite or Laird part numbers to an Amidon-style number may not be evident. Clifton labs has excellent webpages of examples and is also a good way to find the cores sizes and materials commonly stocked at the mainline distributors using the manufacturer's part number (often with cross-ref to Amidon style number as a strong hint!) Recently some here expressed concern that the mini-circuits part may saturate with medium DC currents. Of course if you are doing a SMT production run you don't want to use bigger cores than necessary and most of the mini-circuits parts tend to be physically very tiny to meet this market. But if you wind your own on bigger cores this is a non-issue. Tim N3QE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Again I refer you to Clifton Labs website and cross-references there to the Fair-Rite part numbers/mixes. Although the marketing largely emphasizes EMI suppression, all the mainline distributors now offer several mixes and core styles that are perfect for RF transformers. Powdered iron, yeah, those are not so easily found at mainline distributors, I end up getting them from kitsandparts.com or Amidon. And to Jim's point... build your own MMIC from discrete RF transistors (often different generations of CATV-oriented transistors - you get the advantage that you get tune bias currents etc. for individual need) is quite easy using parts stocked at Mouser etc. They also have these impressive super-beefy broadband CATV distribution/isolation amplifiers. Tim N3QE On Thu, Nov 27, 2014 at 12:49 PM, Bob Camp kb...@n1k.org wrote: Hi At least last time I looked, the “easy to find” distributors had great selections of parts used for switching power supplies and EMI suppression. When you started to dig for the specialized parts for RF transformers and tuned filters, the stock was pretty thin to nonexistent. If you move from ferrite to powdered iron, the search process alway has been more difficult... Bob On Nov 27, 2014, at 11:09 AM, Tim Shoppa tsho...@gmail.com wrote: On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp kb...@n1k.org wrote: The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. The mainline distributors (Allied, Newark, Mouser, etc.) have excellent selection of Fair-Rite and other cores. Admittedly to a neophyte the equivalence of Fair-Rite or Laird part numbers to an Amidon-style number may not be evident. Clifton labs has excellent webpages of examples and is also a good way to find the cores sizes and materials commonly stocked at the mainline distributors using the manufacturer's part number (often with cross-ref to Amidon style number as a strong hint!) Recently some here expressed concern that the mini-circuits part may saturate with medium DC currents. Of course if you are doing a SMT production run you don't want to use bigger cores than necessary and most of the mini-circuits parts tend to be physically very tiny to meet this market. But if you wind your own on bigger cores this is a non-issue. Tim N3QE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/27/2014 7:07 AM, Tim Shoppa wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE You need the tiny cores to get the performance of the MiniCircuits transformers. You just can't get the same bandwidth using macro sized binocular cores. Now, if you don't need a lot of bandwidth, then what you are saying could make sense. Another issue is stray capacitance. Considerably lower with a tiny core. I have spent many hours characterizing MiniCircuits transformers beyond the data sheet specs, and dissecting them to learn how they do it. They really do have a lot of rocket science in them. In terms of the engineering I am buying (especially in a one-off application) they are ridiculously cheap. And I say that as a fairly knowledgeable transformer designer in my own right. I do keep binocular cores around for higher power transformers, and for emergencies when I need a transformer yesterday. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/27/2014 9:09 AM, Tim Shoppa wrote: On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp kb...@n1k.org wrote: The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. The mainline distributors (Allied, Newark, Mouser, etc.) have excellent selection of Fair-Rite and other cores. Admittedly to a neophyte the equivalence of Fair-Rite or Laird part numbers to an Amidon-style number may not be evident. I recently needed some binocular cores for a transformer for a client. After checking all the distributors, I had to buy 500 of them. Minimum quantity. So much for one-off hobbyist projects. The reason why I did not use a MiniCircuits transformer for this client is that the impedance was much less than 50 ohms. This is one area that MiniCircuits really does not address. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Another reason is reproducibility. If you or someone else wants to reproduce your design, using a well defined and available commercial part makes it much easier to achieve the same performance, particularly for RF components. Didier KO4BB On November 27, 2014 12:41:34 PM CST, Richard (Rick) Karlquist rich...@karlquist.com wrote: On 11/27/2014 7:07 AM, Tim Shoppa wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE You need the tiny cores to get the performance of the MiniCircuits transformers. You just can't get the same bandwidth using macro sized binocular cores. Now, if you don't need a lot of bandwidth, then what you are saying could make sense. Another issue is stray capacitance. Considerably lower with a tiny core. I have spent many hours characterizing MiniCircuits transformers beyond the data sheet specs, and dissecting them to learn how they do it. They really do have a lot of rocket science in them. In terms of the engineering I am buying (especially in a one-off application) they are ridiculously cheap. And I say that as a fairly knowledgeable transformer designer in my own right. I do keep binocular cores around for higher power transformers, and for emergencies when I need a transformer yesterday. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
YES! That's exactly why I go to Mini-Circuits. Jim On 11/27/2014 2:03 PM, Didier Juges wrote: Another reason is reproducibility. If you or someone else wants to reproduce your design, using a well defined and available commercial part makes it much easier to achieve the same performance, particularly for RF components. Didier KO4BB On November 27, 2014 12:41:34 PM CST, Richard (Rick) Karlquist rich...@karlquist.com wrote: On 11/27/2014 7:07 AM, Tim Shoppa wrote: For a hobbyist doing things a few at a time, what advantage is there to buying RF transformers made by Mini-circuits etc., vs winding them using commonly available ferrite cores/binocular cores? If I needed to do a production run of 1000+ boards with tiny SMT transformers, sure, no problem buying them from mini-circuits or a distributor etc. But for hobbyist stuff seems far more flexible to wind them onesy-twosy using not so tiny cores and windings selected for the particular application. Tim N3QE You need the tiny cores to get the performance of the MiniCircuits transformers. You just can't get the same bandwidth using macro sized binocular cores. Now, if you don't need a lot of bandwidth, then what you are saying could make sense. Another issue is stray capacitance. Considerably lower with a tiny core. I have spent many hours characterizing MiniCircuits transformers beyond the data sheet specs, and dissecting them to learn how they do it. They really do have a lot of rocket science in them. In terms of the engineering I am buying (especially in a one-off application) they are ridiculously cheap. And I say that as a fairly knowledgeable transformer designer in my own right. I do keep binocular cores around for higher power transformers, and for emergencies when I need a transformer yesterday. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/27/2014 11:03 AM, Didier Juges wrote: Another reason is reproducibility. If you or someone else wants to reproduce your design, using a well defined and available commercial part makes it much easier to achieve the same performance, particularly for RF components. Didier KO4BB Exactly right. I wrote an article on receiving loops and showed a design with a 50:5 (turns ratio) transformer wound on a toroid. Again, this is not available from MiniCircuits. I have wasted time dealing with numerous dumb questions about can I use XXX core that I have laying around the lab? or can I use a different gauge wire to wind it, etc. So many people complained about the shipping cost to buy one core that I stocked the cores and included them with PC boards I was already selling to reduce the shipping cost to zero. BTW, 73 material would NOT work in this application. I was asked about that multiple times even though the article specifically said it would not work and explained why. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Mouser carries a selection from Fair-Rite. They don't make it easy to find a specific part number, however. http://www.mouser.com/Fair-Rite/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9?P=1z13m3cZ1yxh9di Joe Gray W5JG On Thu, Nov 27, 2014 at 11:34 AM, Tim Shoppa tsho...@gmail.com wrote: Again I refer you to Clifton Labs website and cross-references there to the Fair-Rite part numbers/mixes. Although the marketing largely emphasizes EMI suppression, all the mainline distributors now offer several mixes and core styles that are perfect for RF transformers. Powdered iron, yeah, those are not so easily found at mainline distributors, I end up getting them from kitsandparts.com or Amidon. And to Jim's point... build your own MMIC from discrete RF transistors (often different generations of CATV-oriented transistors - you get the advantage that you get tune bias currents etc. for individual need) is quite easy using parts stocked at Mouser etc. They also have these impressive super-beefy broadband CATV distribution/isolation amplifiers. Tim N3QE On Thu, Nov 27, 2014 at 12:49 PM, Bob Camp kb...@n1k.org wrote: Hi At least last time I looked, the easy to find distributors had great selections of parts used for switching power supplies and EMI suppression. When you started to dig for the specialized parts for RF transformers and tuned filters, the stock was pretty thin to nonexistent. If you move from ferrite to powdered iron, the search process alway has been more difficult... Bob On Nov 27, 2014, at 11:09 AM, Tim Shoppa tsho...@gmail.com wrote: On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp kb...@n1k.org wrote: The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. The mainline distributors (Allied, Newark, Mouser, etc.) have excellent selection of Fair-Rite and other cores. Admittedly to a neophyte the equivalence of Fair-Rite or Laird part numbers to an Amidon-style number may not be evident. Clifton labs has excellent webpages of examples and is also a good way to find the cores sizes and materials commonly stocked at the mainline distributors using the manufacturer's part number (often with cross-ref to Amidon style number as a strong hint!) Recently some here expressed concern that the mini-circuits part may saturate with medium DC currents. Of course if you are doing a SMT production run you don't want to use bigger cores than necessary and most of the mini-circuits parts tend to be physically very tiny to meet this market. But if you wind your own on bigger cores this is a non-issue. Tim N3QE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi Finding the RF transformer parts is still a bit of a challenge. Bob On Nov 27, 2014, at 4:21 PM, Joseph Gray jg...@zianet.com wrote: Mouser carries a selection from Fair-Rite. They don't make it easy to find a specific part number, however. http://www.mouser.com/Fair-Rite/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9?P=1z13m3cZ1yxh9di Joe Gray W5JG On Thu, Nov 27, 2014 at 11:34 AM, Tim Shoppa tsho...@gmail.com wrote: Again I refer you to Clifton Labs website and cross-references there to the Fair-Rite part numbers/mixes. Although the marketing largely emphasizes EMI suppression, all the mainline distributors now offer several mixes and core styles that are perfect for RF transformers. Powdered iron, yeah, those are not so easily found at mainline distributors, I end up getting them from kitsandparts.com or Amidon. And to Jim's point... build your own MMIC from discrete RF transistors (often different generations of CATV-oriented transistors - you get the advantage that you get tune bias currents etc. for individual need) is quite easy using parts stocked at Mouser etc. They also have these impressive super-beefy broadband CATV distribution/isolation amplifiers. Tim N3QE On Thu, Nov 27, 2014 at 12:49 PM, Bob Camp kb...@n1k.org wrote: Hi At least last time I looked, the easy to find distributors had great selections of parts used for switching power supplies and EMI suppression. When you started to dig for the specialized parts for RF transformers and tuned filters, the stock was pretty thin to nonexistent. If you move from ferrite to powdered iron, the search process alway has been more difficult... Bob On Nov 27, 2014, at 11:09 AM, Tim Shoppa tsho...@gmail.com wrote: On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp kb...@n1k.org wrote: The main complaint is the difficulty of getting the correct cores. I seem to have a few dozen bags of cores. The mainline distributors (Allied, Newark, Mouser, etc.) have excellent selection of Fair-Rite and other cores. Admittedly to a neophyte the equivalence of Fair-Rite or Laird part numbers to an Amidon-style number may not be evident. Clifton labs has excellent webpages of examples and is also a good way to find the cores sizes and materials commonly stocked at the mainline distributors using the manufacturer's part number (often with cross-ref to Amidon style number as a strong hint!) Recently some here expressed concern that the mini-circuits part may saturate with medium DC currents. Of course if you are doing a SMT production run you don't want to use bigger cores than necessary and most of the mini-circuits parts tend to be physically very tiny to meet this market. But if you wind your own on bigger cores this is a non-issue. Tim N3QE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi On Nov 27, 2014, at 5:10 PM, Gerhard Hoffmann dk...@arcor.de wrote: Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT To get back to the original post: Which Fair-Rite cores listed on Mouser can be used for making transformers? There are a variety of people making pre-wound parts. Bob http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
On 11/27/14, 3:10 PM, Gerhard Hoffmann wrote: Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. Analog Devices seems to use these for their various application circuits Up to 3 GHz is the Mini-Circuits TC1-1-13. From 3 GHz to 4 GHz is the Johanson Technology 3600BL14M050. From 4.9 GHz to 6 GHz is the Johanson Technology 5400BL15B050. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
43 binocular core: 2843002402, 14 cents qty 1 at Mouser. 77 binocular core: 2873000202, 59 cents qty 1 at Newark. 43 material toroid: 5943000201, 12 cents qty 1 at Mouser. Clifton Labs has good examples and measurements on transformers wound on these and other cores. On Thu, Nov 27, 2014 at 6:54 PM, Bob Camp kb...@n1k.org wrote: To get back to the original post: Which Fair-Rite cores listed on Mouser can be used for making transformers? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi On Nov 27, 2014, at 5:59 PM, Jim Lux jim...@earthlink.net wrote: On 11/27/14, 3:10 PM, Gerhard Hoffmann wrote: Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. Analog Devices seems to use these for their various application circuits Up to 3 GHz is the Mini-Circuits TC1-1-13. From 3 GHz to 4 GHz is the Johanson Technology 3600BL14M050. From 4.9 GHz to 6 GHz is the Johanson Technology 5400BL15B050. For pre-wound parts, there are a number of outfits that will sell you sub $1 transformers. How well they work .. who knows. One example: http://www.digikey.com/product-detail/en/MABA-007159-00/1465-1302-2-ND/4429718 There are other parts in the same series at similar prices. Don’t want to go for the 2K pc minimum order? Price roughly doubles. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Here are a couple of links to some Fair-Rite documentation that can help you determine which cores will work for broadband transformers Use of Ferrites in Broadband Transformers http://www.fair-rite.com/newfair/pdf/Broadband.pdf And the current Fair-Rite product catalog http://www.fair-rite.com/newfair/pdf/Fair-Rite_Catalog_17th_Edition.pdf HTH, Dave M Bob Camp wrote: Hi On Nov 27, 2014, at 5:10 PM, Gerhard Hoffmann dk...@arcor.de wrote: Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT To get back to the original post: Which Fair-Rite cores listed on Mouser can be used for making transformers? There are a variety of people making pre-wound parts. Bob http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi Those are the sort of parts I was looking for. There are about 10 of them listed at Mouser, all with rational prices. That’s a reasonable selection for starters. It’s still (unfortunately) a small selection compared to the full range of product. Bob On Nov 27, 2014, at 6:17 PM, Tim Shoppa tsho...@gmail.com wrote: 43 binocular core: 2843002402, 14 cents qty 1 at Mouser. 77 binocular core: 2873000202, 59 cents qty 1 at Newark. 43 material toroid: 5943000201, 12 cents qty 1 at Mouser. Clifton Labs has good examples and measurements on transformers wound on these and other cores. On Thu, Nov 27, 2014 at 6:54 PM, Bob Camp kb...@n1k.org wrote: To get back to the original post: Which Fair-Rite cores listed on Mouser can be used for making transformers? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Minicircuits 10% discount in December
Hi I’ve been using their products (and their competitors) to make transformers for at least 40 years. It’s amazingly easy to do. The problem has always been finding the raw cores without buying a ton of them at a time. Bob On Nov 27, 2014, at 6:34 PM, Dave M dgmin...@mediacombb.net wrote: Here are a couple of links to some Fair-Rite documentation that can help you determine which cores will work for broadband transformers Use of Ferrites in Broadband Transformers http://www.fair-rite.com/newfair/pdf/Broadband.pdf And the current Fair-Rite product catalog http://www.fair-rite.com/newfair/pdf/Fair-Rite_Catalog_17th_Edition.pdf HTH, Dave M Bob Camp wrote: Hi On Nov 27, 2014, at 5:10 PM, Gerhard Hoffmann dk...@arcor.de wrote: Am 27.11.2014 um 23:30 schrieb Bob Camp: Hi Finding the RF transformer parts is still a bit of a challenge. No. These work quite good for me: CX2074 4:1 CT CX2147 1:1 CT To get back to the original post: Which Fair-Rite cores listed on Mouser can be used for making transformers? There are a variety of people making pre-wound parts. Bob http://www.digikey.de/product-search/de/rf-if-and-rfid/balun/3539019?k=cx2074 The 1:1 is optimum for the NIST doubler at the sources, btw. The 4:1 as an autotransformer 9:1 at the drains. (2*BF862). Gives you 13 dBm @ 2f for 13 dBm in at 1f upto 40 MHz in. Still searching a good balun xformer for 800 MHz in.-- 1600 out. regards, Gerhard ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
