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#1
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I have a receiver with some ferrite tuning coils in the IF. In the
process of retuning, attempting to peak the IF, I cracked coils in two cans and they are locked into place. They are in same position from original and the receiver seems fine, makes sensitivity etc. Is there any measurable change to the inductor Q or other parameter when this occurs? I did get replacements but the effort to replace seems difficult. -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
#2
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On Mar 31, 2:34�pm, RFI-EMI-GUY wrote:
I have a receiver with some ferrite tuning coils in the IF. In the process of retuning, attempting to peak the IF, I cracked coils in two cans and they are locked into place. They are in same position from original and the receiver seems fine, makes sensitivity etc. Is there any measurable change to the inductor Q or other parameter when this occurs? I did get replacements but the effort to replace seems difficult. There is PROBABLY no difference. Assuming the usual "455 KHz" IFT, the cores are most probably POWDERED IRON in a binder, not "ferrite." Ferrite is iron powder alloy that is sintered (heated to not quite liquid state) and thus holds itself together without any polymer (plastic) binder. Ferrite cores and structures will produce different results if broken than the manufacturer's data but cannot be predicted. In general, powdered iron cores already have their powder "broken" by suspension in the binder and can be glued/cemented together without undue change. Ferrite things have been used in the microwave region for about 50 years and, for uniformity/reproducibility, require the things to be unbroken to achieve the desired results. But, that is in the region of 1 GHz and above and doesn't apply to the typical IFT. 73, Len AF6AY |
#3
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AF6AY wrote:
On Mar 31, 2:34�pm, RFI-EMI-GUY wrote: I have a receiver with some ferrite tuning coils in the IF. In the process of retuning, attempting to peak the IF, I cracked coils in two cans and they are locked into place. They are in same position from original and the receiver seems fine, makes sensitivity etc. Is there any measurable change to the inductor Q or other parameter when this occurs? I did get replacements but the effort to replace seems difficult. There is PROBABLY no difference. Assuming the usual "455 KHz" IFT, the cores are most probably POWDERED IRON in a binder, not "ferrite." Ferrite is iron powder alloy that is sintered (heated to not quite liquid state) and thus holds itself together without any polymer (plastic) binder. Ferrite cores and structures will produce different results if broken than the manufacturer's data but cannot be predicted. In general, powdered iron cores already have their powder "broken" by suspension in the binder and can be glued/cemented together without undue change. Ferrite things have been used in the microwave region for about 50 years and, for uniformity/reproducibility, require the things to be unbroken to achieve the desired results. But, that is in the region of 1 GHz and above and doesn't apply to the typical IFT. 73, Len AF6AY Thanks for the info! -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
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