Re: [time-nuts] Racal 9420 OCXO
In a message dated 24/08/2011 21:06:33 GMT Daylight Time, robert8...@yahoo.co.uk writes: I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. - Hi Robert Thanks for that information, I've seen similar comments in other manuals re returning for repair but was hoping there might have been something in circulation. regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron GPS antennas
Thread died off is it still going? On Thu, Aug 18, 2011 at 6:32 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 18/08/11 23:49, k4...@aol.com wrote: Hi Magnus, thanks for that information. I had forgotten about that Plessey GP2010 and GP2015 RF chip. The only problem is that you have to do a divide by 7 on the 40 MHz signal that Plessey did in the GP2021 correlator IC. Using an old SuperStar RX is a good reconmendation. Thanks. Doug, k4cle. There is a whole little line of GPS receivers of the same chips. Hacking in external clock onto a SuperStar isn't all that hard. You will not have to do the divide by 7 in this case, For this application you get 35,42 MHz out in the second filter stage, just tap in on that with a diffrential pair after the filter and you are essentially done. In the GP2010/2015 topology it goes back in for AGC and sampler action. If your receiver expects the 35,42 MHz signal, it gets inserted into that place from a receiver buffer with filter and then the rest of the analog and digital path is continued... that's how they use up two GP2010/2015 chips, but can get away with longer cable runs since the damping of 35,42 MHz is much less than that of 1575,42 MHz in RG-58 Cheers, Magnus __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
In a message dated 25/08/2011 17:00:24 GMT Daylight Time, li...@rtty.us writes: Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... -- Who knows what might or might not be contracted out at any given time?, but one at least of the internal PCBs has the Racal logo etched on the track side so I would think it reasonable to assume Racal design and manufacture. Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
On 8/25/2011 9:01 AM, Bob Camp wrote: Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Having just been inside one Bob, I can say for sure, yes, they were made by Racal at I presume Bracknell, the sub assemblies all have racal style part numbers and use similar components to a lot of the instruments of that period. Also having just been in a 9420 I can totally see why they didn't want anyone mucking about inside it. I suspect like the -hp- 10811 there were some adjust on test values that depended on the individual crystals. But all that doesn't apply to us time nuts does it?I didn't consider myself a true nut until I'd been inside and fixed a dead 10811 with an open thermistor :^). In any case Racal as such is long gone and there's no one to return them to any more so we don't have a lot of choice. Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Camp li...@rtty.us wrote: From: Bob Camp li...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
The blue labels just barely visible behind the control panel in the close-up pictures look an awful lot like actual Sulzer labels. I wonder if instead of being licensed it was actually OEM'd and they just replaced the front panel with a purpose-built one. John On 8/25/2011 12:23 PM, Robert Atkinson wrote: I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Campli...@rtty.us wrote: From: Bob Campli...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.comgandal...@aol.com wrote: From: gandal...@aol.comgandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
Hi Bob I will enquire of a friend. I would not be surprised if they were in house manufacture they were used for a very long epriod without changes in design. There is a history of UK firms making their own OCXOs .Pye, Marconi, etc. Racal had a big investment in frequency determination for most of their output went to the military. There are sophisicated standards and Rubidiums in their catalogue. Most of the OCXO (quartz crystal specialist) makers in the UK finished them is sealed cans. Racal were of course the parent of Vodaphone and made a lot of their original site hardware. Alan G3NYK - Original Message - From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Thursday, August 25, 2011 5:01 PM Subject: Re: [time-nuts] Racal 9420 OCXO Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
On 8/25/2011 9:23 AM, Robert Atkinson wrote: I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. I agree Robert. I have maybe a dozen or more Racal receivers here, all the UK ones had Racal made frequency standards. Most of the US built ones had bought in ovens, notably the 6790/GM. The 6772Es came with a nice looking US Racal badged on the outside TCXO all of which however seem now to be faulty, even the NOS spare one I had. Opening them up you find inside a nasty looking plastic OEM module they must have seriously regretted buying :^) Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
Hi If they made them all, then it's probably worth tracing out the circuit. If they actually came from a dozen different places, one circuit could be quite different from the next. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of gandal...@aol.com Sent: Thursday, August 25, 2011 12:08 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Racal 9420 OCXO In a message dated 25/08/2011 17:00:24 GMT Daylight Time, li...@rtty.us writes: Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... -- Who knows what might or might not be contracted out at any given time?, but one at least of the internal PCBs has the Racal logo etched on the track side so I would think it reasonable to assume Racal design and manufacture. Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B units off me in the 90's. http://www.n4iqt.com/fts1000b/1000b-r2.pdf Nice oscillator. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Atkinson Sent: 25 August 2011 5:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Camp li...@rtty.us wrote: From: Bob Camp li...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
Hi …. and *much* better specified performance than the Racal parts. Bob On Aug 25, 2011, at 5:13 PM, Rob Kimberley wrote: I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B units off me in the 90's. http://www.n4iqt.com/fts1000b/1000b-r2.pdf Nice oscillator. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Atkinson Sent: 25 August 2011 5:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Camp li...@rtty.us wrote: From: Bob Camp li...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron GPS antennas
Hi Paul, I am looking into using one of my SuperStar GPS receivers for this. I'll just tap into the circuit at the 35.42 MHz filter. I just need to build up an amplifier for some addional level contol plus providing isolation for the SuperStar. I am going to use the 10 MHz TCXO that's on the receiver to start, then if that much works OK I'll use the 10 MHz signal from the Odetics unit. I'll keep you informed on my progress. 73, Doug, K4cle. Connected by DROID on Verizon Wireless -Original message- From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thu, Aug 25, 2011 15:47:59 GMT+00:00 Subject: Re: [time-nuts] Austron GPS antennas Thread died off is it still going? On Thu, Aug 18, 2011 at 6:32 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 18/08/11 23:49, k4...@aol.com wrote: Hi Magnus, thanks for that information. I had forgotten about that Plessey GP2010 and GP2015 RF chip. The only problem is that you have to do a divide by 7 on the 40 MHz signal that Plessey did in the GP2021 correlator IC. Using an old SuperStar RX is a good reconmendation. Thanks. Doug, k4cle. There is a whole little line of GPS receivers of the same chips. Hacking in external clock onto a SuperStar isn't all that hard. You will not have to do the divide by 7 in this case, For this application you get 35,42 MHz out in the second filter stage, just tap in on that with a diffrential pair after the filter and you are essentially done. In the GP2010/2015 topology it goes back in for AGC and sampler action. If your receiver expects the 35,42 MHz signal, it gets inserted into that place from a receiver buffer with filter and then the rest of the analog and digital path is continued... that's how they use up two GP2010/2015 chips, but can get away with longer cable runs since the damping of 35,42 MHz is much less than that of 1575,42 MHz in RG-58 Cheers, Magnus __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time -nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Austron GPS antennas
Good to hear. But I do not see superstar rcvrs around anymore. I thought the thread was on building up a converter? Must have lost the direction at some point. Regards On Thu, Aug 25, 2011 at 7:35 PM, k4...@aol.com k4...@aol.com wrote: Hi Paul, I am looking into using one of my SuperStar GPS receivers for this. I'll just tap into the circuit at the 35.42 MHz filter. I just need to build up an amplifier for some addional level contol plus providing isolation for the SuperStar. I am going to use the 10 MHz TCXO that's on the receiver to start, then if that much works OK I'll use the 10 MHz signal from the Odetics unit. I'll keep you informed on my progress. 73, Doug, K4cle. Connected by DROID on Verizon Wireless -Original message- From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thu, Aug 25, 2011 15:47:59 GMT+00:00 Subject: Re: [time-nuts] Austron GPS antennas Thread died off is it still going? On Thu, Aug 18, 2011 at 6:32 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 18/08/11 23:49, k4...@aol.com wrote: Hi Magnus, thanks for that information. I had forgotten about that Plessey GP2010 and GP2015 RF chip. The only problem is that you have to do a divide by 7 on the 40 MHz signal that Plessey did in the GP2021 correlator IC. Using an old SuperStar RX is a good reconmendation. Thanks. Doug, k4cle. There is a whole little line of GPS receivers of the same chips. Hacking in external clock onto a SuperStar isn't all that hard. You will not have to do the divide by 7 in this case, For this application you get 35,42 MHz out in the second filter stage, just tap in on that with a diffrential pair after the filter and you are essentially done. In the GP2010/2015 topology it goes back in for AGC and sampler action. If your receiver expects the 35,42 MHz signal, it gets inserted into that place from a receiver buffer with filter and then the rest of the analog and digital path is continued... that's how they use up two GP2010/2015 chips, but can get away with longer cable runs since the damping of 35,42 MHz is much less than that of 1575,42 MHz in RG-58 Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshtt**ps://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] compensation for resistances value changes due to temp
Hello Folks, I have one of these C-MAC Rakon Double oven oscillators. The oven and electronics run on a 12 vdc supply. For this I am using 2 stages of regulation, first to 18 volts and then to 12 vdc. Both of these are 3 term regulators, I know not the best choice. But its a place to start. I know there are better, quiter regulators out there and that is for the future. The 5 volt control EFC voltage is derived from a 5 K resistor in series with a turn pot 10 turn 5 K multiturn pot'. This method alows me to adjust the EFC voltage with resonable precision. After a few hours I was seeing 1 part in 10-11 drift and which was control by the panel mount. As a test I put my finger on the 5 K carbon resistor to warm it up. After a few seconds I could see the frequency drift and acclerate. After I moved my finger the frequecny slowly returned to normal. Buy I would like to optimize so i guess low temp coefficient resistors. But are the other ways to control this type of drift.?? Is there some way of knowing which way the oscillator is drifting and electrically compenate? For know I plan to move the 5 K resistor, after I get a precison device into the area of the oven and see what happens. Hopfully keeping its temp constant will help a little. Open to all suggestions Thank you all for alloeing me to join this group and all the help you have been. PauLC W1VLF ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Racal 9420 OCXO
Forgive someone revealing his ignorance but what is the pronunciation of Racal? Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, August 25, 2011 4:37 PM Subject: Re: [time-nuts] Racal 9420 OCXO Hi …. and *much* better specified performance than the Racal parts. Bob On Aug 25, 2011, at 5:13 PM, Rob Kimberley wrote: I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B units off me in the 90's. http://www.n4iqt.com/fts1000b/1000b-r2.pdf Nice oscillator. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Atkinson Sent: 25 August 2011 5:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Camp li...@rtty.us wrote: From: Bob Camp li...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To
Re: [time-nuts] Racal 9420 OCXO
Ray cal Sent from Paragon RC6 Captivate Max Robinson m...@maxsmusicplace.com wrote: Forgive someone revealing his ignorance but what is the pronunciation of Racal? Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, August 25, 2011 4:37 PM Subject: Re: [time-nuts] Racal 9420 OCXO Hi …. and *much* better specified performance than the Racal parts. Bob On Aug 25, 2011, at 5:13 PM, Rob Kimberley wrote: I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B units off me in the 90's. http://www.n4iqt.com/fts1000b/1000b-r2.pdf Nice oscillator. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Atkinson Sent: 25 August 2011 5:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Camp li...@rtty.us wrote: From: Bob Camp li...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] Racal 9420 OCXO
Ray-Kal Max Robinson wrote: Forgive someone revealing his ignorance but what is the pronunciation of Racal? Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Bob Camp li...@rtty.us To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, August 25, 2011 4:37 PM Subject: Re: [time-nuts] Racal 9420 OCXO Hi …. and *much* better specified performance than the Racal parts. Bob On Aug 25, 2011, at 5:13 PM, Rob Kimberley wrote: I seem to remember Racal in the UK buying some Datum (FTS Division) 1000B units off me in the 90's. http://www.n4iqt.com/fts1000b/1000b-r2.pdf Nice oscillator. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Atkinson Sent: 25 August 2011 5:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO I'm pretty sure Racal made these. They are of consistent design over different models and many years and are unlike any other manufacturers OXCO I've seen. Racal were old school and did prettymuch everything themselves. The did do what appears to be a licence built Sulzer though. The MA-259, see http://www.radiomuseum.org/r/racal_precision_frequency_stan.html Regards, Robert G8RPI. --- On Thu, 25/8/11, Bob Camp li...@rtty.us wrote: From: Bob Camp li...@rtty.us Subject: Re: [time-nuts] Racal 9420 OCXO To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Date: Thursday, 25 August, 2011, 17:01 Hi Do we know for sure that Racal actually made these OCXO's in house? My *guess* is that they were made by various companies over the years and sold to Racal. The return for service would have been a return to Racal and then they forward it to the people who made it... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, August 24, 2011 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Racal 9420 OCXO Kind of amazing what time-nuts have in there secret documentation. Though I do not need this thanks for sharing. Regards Paul WB8TSL On Wed, Aug 24, 2011 at 4:05 PM, Robert Atkinson robert8...@yahoo.co.ukwrote: Hi, I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair. Robert G8RPI --- On Wed, 24/8/11, gandal...@aol.com gandal...@aol.com wrote: From: gandal...@aol.com gandal...@aol.com Subject: Re: [time-nuts] Racal 9420 OCXO To: time-nuts@febo.com Date: Wednesday, 24 August, 2011, 16:03 In a message dated 24/08/2011 00:03:19 GMT Daylight Time, dan...@verizon.net writes: I don't think Racal released circuit diagrams of any of their ovens. I have traced out the circuit of the rapid warm up oven found in a lot of receivers, the 9442-12 and have fixed those, there is a ceramic cap that frequently goes wonky. The two 9420s I have fixed were just broken wires; they seem to have used PVC insulated wire which degrades... I haven't done the homework on those yet. The 9420s I have do have an EFC input as well as a stabilised Voltage out to feed it, and in the receivers I have that use it [RA1795] the fine setting is done from that, coarse setting from the top adjustment. - Hi Dan I've taken a further look at the RA1794 manual and see now that it does confirm a fine tune pot being available when using the 9420. Having opened up this oscillator I find there are connections to every pin on the B7G connector so will assume until proven otherwise that it does meet the interface spec shown in the 1794 manual. I suspect the comments I've seen claiming most do not have the EFC option is more a case that in many installations it isn't used, which isn't quite the same thing. Thanks again for your comments. regards Nigel ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list --
