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Mech. Filters for FT-817/8

Peter Burnett All Messages By This Member #114810 The Sotabeam “Laserbeam digital audio filter fitted to the main board would appear to be a serious alternative, or at least worth considering. True or false?? P Burnett -- Peter Burnett G4BLL
Jeff WN1MB All Messages By This Member #114812 开云体育 About the only alternative, though its location in the receiver signal chain limits its effectiveness - compared to limiting the IF bandpass. On 5/16/24 16:18, Peter Burnett via groups.io wrote: toggle quoted message Show quoted text The Sotabeam “Laserbeam digital audio filter fitted to the main board would appear to be a serious alternative, or at least worth considering. True or false?? P Burnett
Peter Burnett All Messages By This Member #114813 开云体育 I have just had the Sotabeam filter board fitted so I hope it does what it says on the tin.? Peter G4BLL P Burnett toggle quoted message Show quoted text On 16 May 2024, at 21:44, Jeff WN1MB <jwbauer@...> wrote: ? About the only alternative, though its location in the receiver signal chain limits its effectiveness - compared to limiting the IF bandpass. On 5/16/24 16:18, Peter Burnett via groups.io wrote: The Sotabeam “Laserbeam digital audio filter fitted to the main board would appear to be a serious alternative, or at least worth considering. True or false?? P Burnett -- Peter Burnett G4BLL
Peter Burnett All Messages By This Member #114814 开云体育 I forgot to mention that a Collins XF-115c has just been sold for ?93 on eBay!? P Burnett toggle quoted message Show quoted text On 16 May 2024, at 23:26, Peter Burnett via groups.io <g4bll.peter@...> wrote: ?I have just had the Sotabeam filter board fitted so I hope it does what it says on the tin.? Peter G4BLL P Burnett On 16 May 2024, at 21:44, Jeff WN1MB <jwbauer@...> wrote: ? About the only alternative, though its location in the receiver signal chain limits its effectiveness - compared to limiting the IF bandpass. On 5/16/24 16:18, Peter Burnett via groups.io wrote: The Sotabeam “Laserbeam digital audio filter fitted to the main board would appear to be a serious alternative, or at least worth considering. True or false?? P Burnett -- Peter Burnett G4BLL -- Peter Burnett G4BLL
robert beswick #114816 开云体育 I have the lazerbeam installed and works really well.? I also have the w4rt dual filter pack installed also. I prefer using the lazerbeam setup.? Robert KA6PSD? Sent from my T-Mobile 5G Device toggle quoted message Show quoted text -------- Original message -------- From: "Peter Burnett via groups.io" <g4bll.peter@...> Date: 5/16/24 3:26 PM (GMT-07:00) To: [email protected] Subject: Re: [ft817] Mech. Filters for FT-817/8 I have just had the Sotabeam filter board fitted so I hope it does what it says on the tin.? Peter G4BLL P Burnett On 16 May 2024, at 21:44, Jeff WN1MB <jwbauer@...> wrote: ? About the only alternative, though its location in the receiver signal chain limits its effectiveness - compared to limiting the IF bandpass. On 5/16/24 16:18, Peter Burnett via groups.io wrote: The Sotabeam “Laserbeam digital audio filter fitted to the main board would appear to be a serious alternative, or at least worth considering. True or false?? P Burnett -- Peter Burnett G4BLL
Ronan Cantwell All Messages By This Member #114817 I have the laserbeam fitted to my 817. It's better than no filter but is far from ideal. It creates images of very strong stations about 1 and a bit kHz away from their true frequency. I can't remember the actual offset as I've not used the radio in a while. This makes it confusing to use in busy conditions. Using the IF shift can mitigate this to some extent. There have been a few times that I've called a station only to realise, after turning off the narrow mode, that I was calling on the image frequency ?.? The filter also messes with the displayed S meter readings in that they're way higher than they should be with the filter engaged. As I said, its better than no filter but not by much. A simple external audio CW filter would be just as good, if not better.? Cheers,? Ronan MM0IVR?
Petr Ourednik All Messages By This Member #114819 Ronan, very well said. These filters are a bit nasty in term of spurious images and related artefacts.? The EMF filters are better in these cases (even although the digital filter has announced far superior shape factor) or even better are crystal filters with better first -30dB skirt and total stop-band rejection ...but these are no available for our FT-8xx radios. What I can recommend in case of first/last aid is SCAF filter. I used for long time the SCAF filter based on NewEnglandQRP club with LMF100 or LTC1060 (do not use the MF10CN and MF10BN chips which are much noisier) and I was amazed with so simply circuit. It cannot beat EMF or even crystal filters but if you have nothing then try it... 73 - Petr, OK1RP
Petr Ourednik All Messages By This Member #114820 Robert, if you will be thinking about selling the W4RT dual filter pack then I will grab it.? Even the filters maybe not needed (if SSB installed) as I need just the board and 300Hz filter if installed. I know that it's just fantasy but just in case... :) Thanks. 73 - Petr, OK1RP
robert beswick #114822 开云体育 I have to say I'm sorry, but I'm one of those guys that has to aquire every accessory or gadget for my radio. Has only taken 5 years to collect all the cool stuff. I have even built/constructed an external box for monitoring all parameters while operating.? Now that I'm retired I will be getting out and doing pota's here in the near future.? It only takes 3 sizable cases for all the the toys. Again I apologize? but not ready to let go. KA6PSD Robert? Sent from my T-Mobile 5G Device toggle quoted message Show quoted text -------- Original message -------- From: "Petr Ourednik via groups.io" <indians@...> Date: 5/17/24 8:16 AM (GMT-07:00) To: [email protected] Subject: Re: [ft817] Mech. Filters for FT-817/8 Robert, if you will be thinking about selling the W4RT dual filter pack then I will grab it.? Even the filters maybe not needed (if SSB installed) as I need just the board and 300Hz filter if installed. I know that it's just fantasy but just in case... :) Thanks. 73 - Petr, OK1RP
Petr Ourednik All Messages By This Member #114824 No problem, Robert. I am the same staff. hi Good luck with POTA's! btw: I am looking for another Yaesu TCXO-9 (only new w/smaller oscillator and not China unit)? -- 73 - Petr, OK1RP FT-817ND \| FT-818ND \| FT-857D?

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