Re: [Flexradio] Low recieve
I nice to get all exercised over gaps and diodes but most lightening damage is through ground loops and the lightening entering the AC seeking its way to ground. In other words this incident my have been less related to stuff on the wire than IC-1 acting as fuse in a ground loop path, especially if there was no direct hit. Static on the other hand can be off the antenna to a high voltage, but they are 2 different animals. 73 W9OY Be a better Globetrotter. Get better travel answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=listsid=396545469 ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
[Flexradio] Low recieve
I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Frank, My best guess is the preamplifier on the RFE-board. Unless the schematic diagram is not recently updated, there are protection diodes (1N4148) before the input capacitor (C47) of the amplifier, so maybe they are broken, too. You possibly can repair it yourself. See these ECOs for help: http://support.flex-radio.com/Downloads.aspx?id=102 http://support.flex-radio.com/Downloads.aspx?id=109 73, Ahti OH2RZ On 17/05/07, Frank Mayer [EMAIL PROTECTED] wrote: I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Sorry, my memory made me a trick. The protection diodes are not shown in the original schematic. They are shown only in the ECO001 and ECO025. Please, FlexRadio, update and publish the schematic diagrams of the SDR-1000. 73, Ahti OH2RZ On 17/05/07, Ahti Aintila [EMAIL PROTECTED] wrote: Frank, My best guess is the preamplifier on the RFE-board. Unless the schematic diagram is not recently updated, there are protection diodes (1N4148) before the input capacitor (C47) of the amplifier, so maybe they are broken, too. You possibly can repair it yourself. See these ECOs for help: http://support.flex-radio.com/Downloads.aspx?id=102 http://support.flex-radio.com/Downloads.aspx?id=109 73, Ahti OH2RZ On 17/05/07, Frank Mayer [EMAIL PROTECTED] wrote: I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Thanks guys. I'll check it out today! - Original Message - From: Ahti Aintila To: Frank Mayer Cc: flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 4:29 AM Subject: Re: [Flexradio] Low recieve Frank, My best guess is the preamplifier on the RFE-board. Unless the schematic diagram is not recently updated, there are protection diodes (1N4148) before the input capacitor (C47) of the amplifier, so maybe they are broken, too. You possibly can repair it yourself. See these ECOs for help: http://support.flex-radio.com/Downloads.aspx?id=102 http://support.flex-radio.com/Downloads.aspx?id=109 73, Ahti OH2RZ On 17/05/07, Frank Mayer [EMAIL PROTECTED] wrote: I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.1/805 - Release Date: 5/15/2007 10:47 AM -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/011b846a/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Re: [Flexradio] Low recieveI called Ken at Flex and he referred me to Ed at Flex service and he walked me thru the RFE board and we determined that the RF amp IC was bad. They are sending one right out to me. Great service! Great radio! You gotta love it! Thanks guys! Frank, WA3JBT - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] ; Frank Mayer ; flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 5:54 AM Subject: RE: [Flexradio] Low recieve It might be usefull to check if the relay contacts on the input of the RF preamp are still OK (if the diodes are damaged) good luck 73 de peter pa0pvn groeten Peter petervn(a)hetnet.nl ; pa0pvn(a)hetnet.nl ; pa0pvn(a)gmail.com ; pa0pvn(a)amsat.org . -- Van: [EMAIL PROTECTED] namens Gerd Loch Verzonden: do 17-5-2007 11:52 Aan: 'Frank Mayer'; flexradio@flex-radio.biz Onderwerp: Re: [Flexradio] Low recieve Hi Frank, besides the protection diodes and the preamplifier itself (as stated by Ahti) the next sensitive circuit is the switch FST3252M (IC1). You can check if the bias dc-voltage (2,5V) can be measured at the output pins. 73 Gerd, DJ8AY -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Frank Mayer Sent: Thursday, May 17, 2007 9:36 AM To: flexradio@flex-radio.biz Subject: [Flexradio] Low recieve I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20 070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.1/805 - Release Date: 5/15/2007 10:47 AM -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/3478708a/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Frank, That's been my experience as well (with the few minor issues I've had.) I also appreciate seeing these questions posted to the the list and all the valuable suggestions. Thanks for posting the question and the outcome. Mark -Original Message- From: Frank Mayer [mailto:[EMAIL PROTECTED] Sent: Thursday, May 17, 2007 10:58 AM To: flexradio@flex-radio.biz Subject: Re: [Flexradio] Low recieve Re: [Flexradio] Low recieveI called Ken at Flex and he referred me to Ed at Flex service and he walked me thru the RFE board and we determined that the RF amp IC was bad. They are sending one right out to me. Great service! Great radio! You gotta love it! Thanks guys! Frank, WA3JBT - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] ; Frank Mayer ; flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 5:54 AM Subject: RE: [Flexradio] Low recieve It might be usefull to check if the relay contacts on the input of the RF preamp are still OK (if the diodes are damaged) good luck 73 de peter pa0pvn groeten Peter petervn(a)hetnet.nl ; pa0pvn(a)hetnet.nl ; pa0pvn(a)gmail.com ; pa0pvn(a)amsat.org . -- Van: [EMAIL PROTECTED] namens Gerd Loch Verzonden: do 17-5-2007 11:52 Aan: 'Frank Mayer'; flexradio@flex-radio.biz Onderwerp: Re: [Flexradio] Low recieve Hi Frank, besides the protection diodes and the preamplifier itself (as stated by Ahti) the next sensitive circuit is the switch FST3252M (IC1). You can check if the bias dc-voltage (2,5V) can be measured at the output pins. 73 Gerd, DJ8AY -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Frank Mayer Sent: Thursday, May 17, 2007 9:36 AM To: flexradio@flex-radio.biz Subject: [Flexradio] Low recieve I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20 070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.1/805 - Release Date: 5/15/2007 10:47 AM -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/3478708a/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/2cdd85a0/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Hi Frank, To protect the receiver of my SDR1000 I stalled ahead of the RF-amplifier a microgap surge absorber element in discharge tube. See the below link. http://www.koaproducts.com/english/catalogue/sa.htm It may be the right opportunity to install one of these when you unpile the board stack of the SDR1000 for repair. gl de SM6OMH Willi - Original Message - From: Frank Mayer [EMAIL PROTECTED] To: flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 12:35 AM Subject: [Flexradio] Low recieve I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Willi and Frank, The DC Spark-Over Voltage of SA05-C-T52-A-301-M is specified 200V±20% and typically the max. device voltage of the preamps is as low as 5-6V. A properly located microgap surge absorber may prevent big disasters, but still for low voltage transients protective diodes will be needed, too. 73, Ahti OH2RZ On 17/05/07, Willi Reppel [EMAIL PROTECTED] wrote: Hi Frank, To protect the receiver of my SDR1000 I stalled ahead of the RF-amplifier a microgap surge absorber element in discharge tube. See the below link. http://www.koaproducts.com/english/catalogue/sa.htm It may be the right opportunity to install one of these when you unpile the board stack of the SDR1000 for repair. gl de SM6OMH Willi - Original Message - From: Frank Mayer [EMAIL PROTECTED] To: flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 12:35 AM Subject: [Flexradio] Low recieve ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Frank et all, Here is are a couple of inexpensive devices that I use. I.C.E. makes some great products and they are of the highest quality. http://www.iceradioproducts.com/impulse1.html#1 (transmission lines) http://www.iceradioproducts.com/reconly.html#rflimiter (receiver input only) Saved my bacon a few times! --Larry W8ER Frank Mayer wrote: Re: [Flexradio] Low recieveI called Ken at Flex and he referred me to Ed at Flex service and he walked me thru the RFE board and we determined that the RF amp IC was bad. They are sending one right out to me. Great service! Great radio! You gotta love it! Thanks guys! Frank, WA3JBT - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] ; Frank Mayer ; flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 5:54 AM Subject: RE: [Flexradio] Low recieve It might be usefull to check if the relay contacts on the input of the RF preamp are still OK (if the diodes are damaged) good luck 73 de peter pa0pvn groeten Peter petervn(a)hetnet.nl ; pa0pvn(a)hetnet.nl ; pa0pvn(a)gmail.com ; pa0pvn(a)amsat.org . -- Van: [EMAIL PROTECTED] namens Gerd Loch Verzonden: do 17-5-2007 11:52 Aan: 'Frank Mayer'; flexradio@flex-radio.biz Onderwerp: Re: [Flexradio] Low recieve Hi Frank, besides the protection diodes and the preamplifier itself (as stated by Ahti) the next sensitive circuit is the switch FST3252M (IC1). You can check if the bias dc-voltage (2,5V) can be measured at the output pins. 73 Gerd, DJ8AY -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Frank Mayer Sent: Thursday, May 17, 2007 9:36 AM To: flexradio@flex-radio.biz Subject: [Flexradio] Low recieve I have had my SDR for about 6 months now and last night night it was subjected to a static discharge during a thunderstorm. Not a direct hit but enough to affect the receiver. Now it has very low sensitivity. Are there any known causes for this (blown diodes or RF amp transistor in the front end)? Or does it need factory repair. Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20 070517/386eda1e/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.1/805 - Release Date: 5/15/2007 10:47 AM -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/3478708a/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/ ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Ahti and Frank, Sorry, I did not mention that I installed the microgap absorber between antenna input of the RFE board and said voltage transients protective diode on the RFE board. I think nowadays new SDR1000 are already equipped with these diodes while I had to add them according to ECO 001. Remains to be seen how Flexradio protects the SDR 5000 investors against transients. gl es gn de SM6OMH Willi - Original Message - From: Ahti Aintila [EMAIL PROTECTED] To: Willi Reppel [EMAIL PROTECTED] Cc: Frank Mayer [EMAIL PROTECTED]; flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 11:22 AM Subject: Re: [Flexradio] Low recieve Willi and Frank, The DC Spark-Over Voltage of SA05-C-T52-A-301-M is specified 200V±20% and typically the max. device voltage of the preamps is as low as 5-6V. A properly located microgap surge absorber may prevent big disasters, but still for low voltage transients protective diodes will be needed, too. 73, Ahti OH2RZ On 17/05/07, Willi Reppel [EMAIL PROTECTED] wrote: Hi Frank, To protect the receiver of my SDR1000 I stalled ahead of the RF-amplifier a microgap surge absorber element in discharge tube. See the below link. http://www.koaproducts.com/english/catalogue/sa.htm It may be the right opportunity to install one of these when you unpile the board stack of the SDR1000 for repair. gl de SM6OMH Willi - Original Message - From: Frank Mayer [EMAIL PROTECTED] To: flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 12:35 AM Subject: [Flexradio] Low recieve ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
Point of information: My Preamp IC was blown and the protective diodes are still good. I think the diodes are designed to protect against strong RF signals not lightning related atmospheric static. - Original Message - From: Willi Reppel To: Ahti Aintila Cc: Frank Mayer ; flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 3:44 PM Subject: Re: [Flexradio] Low recieve Ahti and Frank, Sorry, I did not mention that I installed the microgap absorber between antenna input of the RFE board and said voltage transients protective diode on the RFE board. I think nowadays new SDR1000 are already equipped with these diodes while I had to add them according to ECO 001. Remains to be seen how Flexradio protects the SDR 5000 investors against transients. gl es gn de SM6OMH Willi - Original Message - From: Ahti Aintila [EMAIL PROTECTED] To: Willi Reppel [EMAIL PROTECTED] Cc: Frank Mayer [EMAIL PROTECTED]; flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 11:22 AM Subject: Re: [Flexradio] Low recieve Willi and Frank, The DC Spark-Over Voltage of SA05-C-T52-A-301-M is specified 200V±20% and typically the max. device voltage of the preamps is as low as 5-6V. A properly located microgap surge absorber may prevent big disasters, but still for low voltage transients protective diodes will be needed, too. 73, Ahti OH2RZ On 17/05/07, Willi Reppel [EMAIL PROTECTED] wrote: Hi Frank, To protect the receiver of my SDR1000 I stalled ahead of the RF-amplifier a microgap surge absorber element in discharge tube. See the below link. http://www.koaproducts.com/english/catalogue/sa.htm It may be the right opportunity to install one of these when you unpile the board stack of the SDR1000 for repair. gl de SM6OMH Willi - Original Message - From: Frank Mayer [EMAIL PROTECTED] To: flexradio@flex-radio.biz Sent: Thursday, May 17, 2007 12:35 AM Subject: [Flexradio] Low recieve -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.1/807 - Release Date: 5/16/2007 6:05 PM -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070517/3e286afb/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Low recieve
At 12:44 PM 5/17/2007, Willi Reppel wrote: Ahti and Frank, Sorry, I did not mention that I installed the microgap absorber between antenna input of the RFE board and said voltage transients protective diode on the RFE board. I think nowadays new SDR1000 are already equipped with these diodes while I had to add them according to ECO 001. Remains to be seen how Flexradio protects the SDR 5000 investors against transients. There's always a tradeoff in transient suppression. Putting diodes in the front puts a capacitance across the input as well as possibly a source of intermods. A spark gap like device can also actually induce transients in the victim circuitry. Imagine a spark gap across a section of openwire line. A transient comes down one side, the sparkgap fires and shorts, with the resultant current spike flowing in the source side of the line, thru the gap, and back out the source line. That current creates a magnetic field which induces a voltage in any other loop near by, including that formed by the receiver input, the two wires in the line, and the (now shorted) sparkgap. I don't have the part number handy, but there are semiconductor transient suppression devices specifically intended for this sort of application with a fairly low threshold voltage, very low parasitic C, and a I/V characteristic designed to minimize IMD. There's also all sorts of subtleties of interconnecting multiple transient suppression devices. For instance, on the AC line, if you have a 250V suppressor at the service entrance and a 170V suppressor on a plug strip, the low energy, low voltage suppressor will protect the big, high energy, higher voltage suppressor by firing (and failing) first. This is without considering all the stray path and transmission line effects. ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
