EMRFD Message Archive 14684

Message	Date	From	Subject
14684	2018-05-01 01:55:21	Ashhar Farhan	Cores for VHF/UHF balanced mixers
What cores can we use to produce broadband mixer and amplifier cores upto 500 MHz? I know that the SBL-1, ADE-1, etc can all be used to this frequency. the -43 in my junkbox gave terrible results. - f
14685	2018-05-01 03:23:43	Thomas S. Knutsen	Re: Cores for VHF/UHF balanced mixers
Try -61 cores. If you are doing just VHF/UHF, you could as well try some airwound coils, but watch the electromagnetism, balance is going to hurt if the coils radiate too much. 73 Thomas. 2018-04-28 7:19 GMT+02:00 Ashhar Farhan farhanbox@gmail.com [emrfd] <emrfd@yahoogroups.com>:   What cores can we use to produce broadband mixer and amplifier cores upto 500 MHz? I know that the SBL-1, ADE-1, etc can all be used to this frequency. the -43 in my junkbox gave terrible results. - f
14688	2018-05-01 06:34:20	Ashhar Farhan	Re: Cores for VHF/UHF balanced mixers
Thanks. I will order some - 61 balun cores. - f
14712	2018-05-02 21:49:26	Raj	Re: Cores for VHF/UHF balanced mixers
Farhan, The old TAP washers are worth a try. I have seen plastic toroids with coils on them in commercial equipment. Raj At 01-05-18, you wrote:   Thanks. I will order some - 61 balun cores. - f
14735	2018-05-03 08:39:47	kb1gmx	Re: Cores for VHF/UHF balanced mixers
Cores for UHF and VHF mixers are usually ferrite and very small as the total wire vs turns need to be accounted for. For example the core I've used at 500mhz is the BN61-2402 that is  .27x.25x.16 inches (7x6,2x4.2mm).  I also have some smaller BN61 cores that are about half that.  Those are both two hole cores.  For 6M to about 500mhz that will do well. The larger was about as big as you can go for cores as then the wires are more significant.  Hint keep  all leads really short, use stripline or airline (stripline elevated over conductive substrate).  Every lead  and wire is likely to be significant at 430. Generally its easier to make band specific mixer at 432 or easier still (excluding cost) buy one. Minicircuits ADE1-ASK is a level 7 mixer good for 2 to 600mhz.  I've used these at 432 with good  result. Allison/Kb1GMX