开云体育

Yaesu replacing ceramic filters in 2 radios - electromigration

Andrew Russell All Messages By This Member #19251 开云体育 ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Andrew Russell Sent: Thursday, 24 March 2022 7:24 AM To: [email protected] Subject: Re: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios ? Found the service manual. The 450KHz IF filter and a 47.25MHz filter do have DC on the inputs. Found the IF filter. Not such a good choice. Andrew VK5CV ? ? From: [email protected] <[email protected]> On Behalf Of Andrew Russell Sent: Thursday, 24 March 2022 6:59 AM To: [email protected] Subject: Re: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios ? Morning all, Fortunately, my FT60r is still going strong. A few years ago I replaced a ceramic filter in a Uniden UHF HT for my brother. The only through hole part on the board. The problem is called electromigration. In that case a combination of loss of hermeticity and DC on the device causes the metallisation to migrate off the ceramic element shifting it’s frequency. They should have a capacitor on the in and out to block DC for long life. Not so easy to achieve. Anyone with a schematic for the FT60r? Andrew VK5CV. ? ? From: [email protected] <[email protected]> On Behalf Of Avi Zamites Sent: Thursday, 24 March 2022 4:16 AM To: [email protected] Subject: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios ? Greetings,? We have 2 FT-60R radios. A few months ago, the audio began sounding distorted. Sort of like when you have a weak battery and there's enough juice to get some audio out, but not clearly... We tried swapping batteries (fully charged) but no difference... The audio was that way when receiving from another FT-60R or from our base station. Simplex or via a repeater. Seemed to happen after several minutes of powering up. Sent them back for warranty repair and the tech said they both checked good. I explained they needed to be on and used several minutes before the issue shows up. He agreed to continue bench testing, then ship them back. He said to record the issue next time. I just called and they said they are waiting for ceramic filters to come in so they can be repaired and returned. Can the IF filters cause such receive distortion? Can they just go bad without any physical damage? Just curious... Any thoughts on the audio? At first I thought the front end was saturated by being close to the transmitting radios, but even 100 feet away from my mobile radio it had this issue...? New to the group.? Thanks.?
Avi Zamites #19252 开云体育 Thanks! Maybe we just caught a bad batch...? Very good information!? 73 N1KSP & N1CHX? Avi Zamites Proud Navy Veteran toggle quoted message Show quoted text From: [email protected] <[email protected]> on behalf of Andrew Russell <vk5zuc@...> Sent: Wednesday, March 23, 2022 5:01:58 PM To: [email protected] <[email protected]> Subject: Re: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios - electromigration ? ? From: [email protected] <[email protected]> On Behalf Of Andrew Russell Sent: Thursday, 24 March 2022 7:24 AM To: [email protected] Subject: Re: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios ? Found the service manual. The 450KHz IF filter and a 47.25MHz filter do have DC on the inputs. Found the IF filter. Not such a good choice. Andrew VK5CV ? ? From: [email protected] <[email protected]> On Behalf Of Andrew Russell Sent: Thursday, 24 March 2022 6:59 AM To: [email protected] Subject: Re: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios ? Morning all, Fortunately, my FT60r is still going strong. A few years ago I replaced a ceramic filter in a Uniden UHF HT for my brother. The only through hole part on the board. The problem is called electromigration. In that case a combination of loss of hermeticity and DC on the device causes the metallisation to migrate off the ceramic element shifting it’s frequency. They should have a capacitor on the in and out to block DC for long life. Not so easy to achieve. Anyone with a schematic for the FT60r? Andrew VK5CV. ? ? From: [email protected] <[email protected]> On Behalf Of Avi Zamites Sent: Thursday, 24 March 2022 4:16 AM To: [email protected] Subject: [Yaesu-FT-60] Yaesu replacing ceramic filters in 2 radios ? Greetings,? We have 2 FT-60R radios. A few months ago, the audio began sounding distorted. Sort of like when you have a weak battery and there's enough juice to get some audio out, but not clearly... We tried swapping batteries (fully charged) but no difference... The audio was that way when receiving from another FT-60R or from our base station. Simplex or via a repeater. Seemed to happen after several minutes of powering up. Sent them back for warranty repair and the tech said they both checked good. I explained they needed to be on and used several minutes before the issue shows up. He agreed to continue bench testing, then ship them back. He said to record the issue next time. I just called and they said they are waiting for ceramic filters to come in so they can be repaired and returned. Can the IF filters cause such receive distortion? Can they just go bad without any physical damage? Just curious... Any thoughts on the audio? At first I thought the front end was saturated by being close to the transmitting radios, but even 100 feet away from my mobile radio it had this issue...? New to the group.? Thanks.?

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