[GPS_Standard] GPS_Standard Digest, Vol 69, Issue 2

Wed Dec 17 18:48:35 EST 2014

I use a Morion MV89A OCXO with my GPSDO.  Available on eBay for good
prices and only requires 12v and +5v.  They are a very stable double
oven oscillator.

Jim
JG1KGS

On 12/15/14, gps_standard-request at mailman.qth.net
<gps_standard-request at mailman.qth.net> wrote:
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>    1. Re: -5 to +5 Voltage Source (Mark Fancher)
>    2. Re: -5 to +5 Voltage Source (w0ep at w0ep.us)
>    3. Re: -5 to +5 Voltage Source (w0ep at w0ep.us)
>    4. Re: -5 to +5 Voltage Source (Zack Widup)
>    5. Re: -5 to +5 Voltage Source (SP2IQW)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 14 Dec 2014 07:35:28 -0500
> From: "Mark Fancher" <mark.fancher at twc.com>
> To: <gps_standard at mailman.qth.net>
> Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
> Message-ID: <[email protected]>
> Content-Type: text/plain;	charset="us-ascii"
>
> I guess I should have planned better before I bought the 10811 oscillator.
> I thought these were very popular for these GPSDO projects, but didn't know
> there'd be so much difficulty in providing the adjustment voltage to it.
>
> What oscillator is best for the VE2ZAZ board that hopefully won't require
> the complex external negative voltage scheme?
>
> Mark
>
> -----Original Message-----
> From: GPS_Standard [mailto:gps_standard-bounces at mailman.qth.net] On Behalf
> Of Dave Platt
> Sent: Saturday, December 13, 2014 10:11 PM
> To: gps_standard at mailman.qth.net
> Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
>
>
>> I'm having difficulty understanding how to create the proper voltage
>> source for the VE2ZAZ control board, -5 to +5 volts.  Any suggestions?
>
> There are several approaches.
>
> If you start with a single-voltage supply (say, a +12 or +24 - whatever
> your
> oscillator requires) you can add an additional regulator to get a clean +5
> supply for the board's oscillator-control output.  Since you only need a
> small current, a simple 78L05 regulator and a couple of filter caps would
> be
> all you need.
>
> The -5 is more difficult.  The most straightforward way is to use a
> commercially-made or home-made power supply with both positive and negative
> outputs... say, a +/- 15 (these are relatively common) and then use a
> negative voltage regulator such as a 7905 to regulate the -15 down to -5.
>
> You could buy a kit such as the Chaney C6895 from Electronics Goldmine...
> this has three variable output voltages (positive and negative up to 15
> volts, at 400 mA, and positive up to 21 volts at 1 ampere).  This might be
> your best bet, if 1 amp is enough to run the oscillator with its heater and
> the main VE2ZAZ input - the two low-current outputs could be set to +5 and
> -5 and provided to the VE2ZAZ output circuit.
>
> It *is* possible to start with a single-voltage DC supply, and generate
> positive and negative voltages from it.  It's a bit tricky.  One approach
> is
> to use a switching-type "inverting regulator" to create the negative
> voltage.  Alltronics has a +12 in, -5 out (Astec AA7600), $8 for two.
> These
> switching inverters might not be a great solution for a GPSDO where you
> want
> really low noise, though.
>
> Another approach is to start with something like a 24-volt DC supply, and
> use a 7805 linear regulator to create an "artificial ground" (which then
> becomes the "GND" power input to your VE2ZAZ board).
>
> If I were you I'd probably look for a multiple-output DC power supply...
> Electronics Goldmine, Alltronics, All Electronics, Marlin P Jones are all
> good on-line vendors to check.
>
> And... as an out-of-the-box possibility - although your HP oscillator has a
> -5 to +5 tuning range, there's no law that says you have to actually *use*
> the whole tuning range.  You could have the VE2ZAZ board put out a tuning
> voltage between 0 and 5 (so no negative supply
> required) and use the HP oscillator's "FREQ ADJUST" trimmer to rough-tune
> the oscillator so that it's right about on-frequency when the VE2ZAZ is
> feeding a mid-scale output (2.5 volts) to the oscillator's EFC input.
>
> This would let you get away with just positive power supply voltages to the
> oscillator oven, oscillator input, and VE2ZAZ.
>
>
>
> ______________________________________________________________
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>
> ------------------------------
>
> Message: 2
> Date: Sun, 14 Dec 2014 14:21:23 -0700
> From: <w0ep at w0ep.us>
> To: "Mark Fancher" <mark.fancher at twc.com>,
> 	gps_standard at mailman.qth.net
> Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
> Message-ID:
> 	<20141214142123.c047917b6272adbdbe8692f8c22b6543.245569ab98.wbe at email09.secureserver.net>
> 	
> Content-Type: text/plain; charset="utf-8"
>
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 14 Dec 2014 14:40:08 -0700
> From: <w0ep at w0ep.us>
> To: "Mark Fancher" <mark.fancher at twc.com>,
> 	gps_standard at mailman.qth.net
> Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
> Message-ID:
> 	<20141214144008.c047917b6272adbdbe8692f8c22b6543.22d277e910.wbe at email09.secureserver.net>
> 	
> Content-Type: text/plain; charset="utf-8"
>
>
> I forgot, my GPS unit required +3 VDC, so I have
> a regulator making that also.
>
>
>
> Chris
>
> -------- Original Message --------
> Subject: RE: [GPS_Standard] -5 to +5 Voltage Source
> From: <w0ep at w0ep.us>
> Date: Sun, December 14, 2014 2:21 pm
> To: "Mark Fancher" <mark.fancher at twc.com>, gps_standard at mailman.qth.net
>
>
>
> I am using that one.  It is working well.
>
>
>
> Besides the VE2ZAZ board, the oscillator requires a heater
> voltage and an oscillator voltage.
>
>
> So, in my GPSDO I have supplies for +24, +12, +5 and -5.
> You can run without the +5 if you let the controller board
> produce that for you.  You can run without the -5 if
> you want to go with the plan Dave described of using
> half of the control voltage swing.
>
>
> I start with a +24 (spec calls for anywhere between +20 and +30)
> supply and use regulators to get the +12 and +5.
> Then I have another supply that produces -5.
>
>
> The manual for that oscillator is available at:
>
>
> http://www.leapsecond.com/museum/10811a/10811a.pdf
>
>
>
>
>
>
>
>
>
>   -------- Original Message --------
>  Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
>  From: "Mark Fancher" <mark.fancher at twc.com>
>  Date: Sun, December 14, 2014 5:35 am
>  To: <gps_standard at mailman.qth.net>
>
>  I guess I should have planned better before I bought the 10811
> oscillator.
>  I thought these were very popular for these GPSDO projects, but didn't
> know
>  there'd be so much difficulty in providing the adjustment voltage to
> it.
>
>  What oscillator is best for the VE2ZAZ board that hopefully won't
> require
>  the complex external negative voltage scheme?
>
>  Mark
>
>  -----Original Message-----
>  From: GPS_Standard [mailto:gps_standard-bounces at mailman.qth.net] On
> Behalf
>  Of Dave Platt
>  Sent: Saturday, December 13, 2014 10:11 PM
>  To: gps_standard at mailman.qth.net
>  Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
>
>
>  > I'm having difficulty understanding how to create the proper voltage
>  > source for the VE2ZAZ control board, -5 to +5 volts. Any suggestions?
>
>  There are several approaches.
>
>  If you start with a single-voltage supply (say, a +12 or +24 - whatever
> your
>  oscillator requires) you can add an additional regulator to get a clean
> +5
>  supply for the board's oscillator-control output. Since you only need a
>  small current, a simple 78L05 regulator and a couple of filter caps
> would be
>  all you need.
>
>  The -5 is more difficult. The most straightforward way is to use a
>  commercially-made or home-made power supply with both positive and
> negative
>  outputs... say, a +/- 15 (these are relatively common) and then use a
>  negative voltage regulator such as a 7905 to regulate the -15 down to
> -5.
>
>  You could buy a kit such as the Chaney C6895 from Electronics
> Goldmine...
>  this has three variable output voltages (positive and negative up to 15
>  volts, at 400 mA, and positive up to 21 volts at 1 ampere). This might
> be
>  your best bet, if 1 amp is enough to run the oscillator with its heater
> and
>  the main VE2ZAZ input - the two low-current outputs could be set to +5
> and
>  -5 and provided to the VE2ZAZ output circuit.
>
>  It *is* possible to start with a single-voltage DC supply, and generate
>  positive and negative voltages from it. It's a bit tricky. One approach
> is
>  to use a switching-type "inverting regulator" to create the negative
>  voltage. Alltronics has a +12 in, -5 out (Astec AA7600), $8 for two.
> These
>  switching inverters might not be a great solution for a GPSDO where you
> want
>  really low noise, though.
>
>  Another approach is to start with something like a 24-volt DC supply,
> and
>  use a 7805 linear regulator to create an "artificial ground" (which
> then
>  becomes the "GND" power input to your VE2ZAZ board).
>
>  If I were you I'd probably look for a multiple-output DC power
> supply...
>  Electronics Goldmine, Alltronics, All Electronics, Marlin P Jones are
> all
>  good on-line vendors to check.
>
>  And... as an out-of-the-box possibility - although your HP oscillator
> has a
>  -5 to +5 tuning range, there's no law that says you have to actually
> *use*
>  the whole tuning range. You could have the VE2ZAZ board put out a
> tuning
>  voltage between 0 and 5 (so no negative supply
>  required) and use the HP oscillator's "FREQ ADJUST" trimmer to
> rough-tune
>  the oscillator so that it's right about on-frequency when the VE2ZAZ is
>  feeding a mid-scale output (2.5 volts) to the oscillator's EFC input.
>
>  This would let you get away with just positive power supply voltages to
> the
>  oscillator oven, oscillator input, and VE2ZAZ.
>
>
>
>  ______________________________________________________________
>  GPS_Standard mailing list
>  Home: http://mailman.qth.net/mailman/listinfo/gps_standard
>  Help: http://mailman.qth.net/mmfaq.htm
>  Post: mailto:GPS_Standard at mailman.qth.net
>
>  This list hosted by: http://www.qsl.net
>  Please help support this email list: http://www.qsl.net/donate.html
>
>  ______________________________________________________________
>  GPS_Standard mailing list
>  Home: http://mailman.qth.net/mailman/listinfo/gps_standard
>  Help: http://mailman.qth.net/mmfaq.htm
>  Post: mailto:GPS_Standard at mailman.qth.net
>
>  This list hosted by: http://www.qsl.net
>  Please help support this email list: http://www.qsl.net/donate.html
>
>
> ------------------------------
>
> Message: 4
> Date: Sun, 14 Dec 2014 21:22:53 -0600
> From: Zack Widup <w9sz.zack at gmail.com>
> To: gps_standard <gps_standard at mailman.qth.net>
> Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
> Message-ID:
> 	<CANJxhWjZXasR3Trb9vFST4fxd74ox9-8U0eyv8RsmNvvaTQgdQ at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> The VE2ZAZ design includes a 5 volt positive regulator on the circuit
> board.
>
> To get a negative 5 volts I've used the simple 7660, etc. design that
> just requires a few capacitors. Positive 5 volts in (brought from the
> 7805 on the circuit board) produces -5 volts out. The current demand
> for this circuit is well within the specs of a 7660 or a 7662. I have
> some other circuits that will supply quite a bit more current at
> negative 5 volts. I think the TC962 is one device. The LT1072/1172 is
> another.
>
> 73, Zack W9SZ
>
>
> On 12/13/14, Dave Platt <dplatt at radagast.org> wrote:
>>
>>> I'm having difficulty understanding how to create the proper voltage
>>> source
>>> for the VE2ZAZ control board, -5 to +5 volts.  Any suggestions?
>>
>> There are several approaches.
>>
>> If you start with a single-voltage supply (say, a +12 or +24 - whatever
>> your oscillator requires) you can add an additional regulator to get a
>> clean +5 supply for the board's oscillator-control output.  Since you
>> only need a small current, a simple 78L05 regulator and a couple of
>> filter caps would be all you need.
>>
>> The -5 is more difficult.  The most straightforward way is to use a
>> commercially-made or home-made power supply with both positive and
>> negative outputs... say, a +/- 15 (these are relatively common) and then
>> use a negative voltage regulator such as a 7905 to regulate the -15 down
>> to -5.
>>
>> You could buy a kit such as the Chaney C6895 from Electronics
>> Goldmine... this has three variable output voltages (positive and
>> negative up to 15 volts, at 400 mA, and positive up to 21 volts at 1
>> ampere).  This might be your best bet, if 1 amp is enough to run the
>> oscillator with its heater and the main VE2ZAZ input - the two
>> low-current outputs could be set to +5 and -5 and provided to the VE2ZAZ
>> output circuit.
>>
>> It *is* possible to start with a single-voltage DC supply, and generate
>> positive and negative voltages from it.  It's a bit tricky.  One
>> approach is to use a switching-type "inverting regulator" to create the
>> negative voltage.  Alltronics has a +12 in, -5 out (Astec AA7600), $8
>> for two.  These switching inverters might not be a great solution for a
>> GPSDO where you want really low noise, though.
>>
>> Another approach is to start with something like a 24-volt DC supply,
>> and use a 7805 linear regulator to create an "artificial ground" (which
>> then becomes the "GND" power input to your VE2ZAZ board).
>>
>> If I were you I'd probably look for a multiple-output DC power supply...
>> Electronics Goldmine, Alltronics, All Electronics, Marlin P Jones are
>> all good on-line vendors to check.
>>
>> And... as an out-of-the-box possibility - although your HP oscillator
>> has a -5 to +5 tuning range, there's no law that says you have to
>> actually *use* the whole tuning range.  You could have the VE2ZAZ board
>> put out a tuning voltage between 0 and 5 (so no negative supply
>> required) and use the HP oscillator's "FREQ ADJUST" trimmer to
>> rough-tune the oscillator so that it's right about on-frequency when the
>> VE2ZAZ is feeding a mid-scale output (2.5 volts) to the oscillator's
>> EFC input.
>>
>> This would let you get away with just positive power supply voltages to
>> the oscillator oven, oscillator input, and VE2ZAZ.
>>
>>
>>
>> ______________________________________________________________
>> GPS_Standard mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/gps_standard
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:GPS_Standard at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>
> ------------------------------
>
> Message: 5
> Date: Mon, 15 Dec 2014 08:43:33 +0100
> From: SP2IQW <michal at e2000.gdynia.pl>
> To: gps_standard at mailman.qth.net
> Subject: Re: [GPS_Standard] -5 to +5 Voltage Source
> Message-ID: <548E9125.7000706 at e2000.gdynia.pl>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> My 3 cents in this topic.
>
> If we do not have separate negative power supply the best way is to use
> a MAX662/LMC662/ICL7662 which makes negative voltage by charge pumping
> from a positive voltage  (4.5-20V range), followed by a 79L05 regulator.
> We can get -5V also from MAX232  TTL/RS232 converter (unloaded pin 6
> provides -10V), it should be filtered and regulated for example with 79L05.
>
> Please keep in mind that voltage drop of 79L05 voltage regulator is
> typically 2V and quiescent current  of a regulator is in the range 3-5mA
> and it may be hard to get enough current from MAX232 when higher current
> operational amplifier will be used instead of OPA2705.
>
> If we don't need negative voltage to control OCXO we can even connect
> -5V power path to ground. The OPA2705 amplifier works as rail to rail on
> the input and output what is shown on the original diagram.
>
>
> The known problem is voltage translating between 3,3V CMOS level GPS
> receiver and 5V logic PIC CPU.
> This year Texas Instruments introduced  SN74LV1T...series logic level
> translators.
> http://www.ti.com/lsds/ti/logic/little-logic-little-translation.page?DCMP=hval_sll_log_sn74lv1t_en&HQS=hval-sll-log-sn74lv1t-pp-en
> Simply insert non-inverting functor as SN74LV1T125/126 or ..08 between
> low voltage GPS receiver and 5V PIC microcontroller.
>
> 73, de Michal
> sp2iqw
>
>
>
> W dniu 2014-12-14 o 04:11, Dave Platt pisze:
>>> I'm having difficulty understanding how to create the proper voltage
>>> source
>>> for the VE2ZAZ control board, -5 to +5 volts.  Any suggestions?
>> There are several approaches.
>>
>> If you start with a single-voltage supply (say, a +12 or +24 - whatever
>> your oscillator requires) you can add an additional regulator to get a
>> clean +5 supply for the board's oscillator-control output.  Since you
>> only need a small current, a simple 78L05 regulator and a couple of
>> filter caps would be all you need.
>>
>> The -5 is more difficult.  The most straightforward way is to use a
>> commercially-made or home-made power supply with both positive and
>> negative outputs... say, a +/- 15 (these are relatively common) and then
>> use a negative voltage regulator such as a 7905 to regulate the -15 down
>> to -5.
>>
>> You could buy a kit such as the Chaney C6895 from Electronics
>> Goldmine... this has three variable output voltages (positive and
>> negative up to 15 volts, at 400 mA, and positive up to 21 volts at 1
>> ampere).  This might be your best bet, if 1 amp is enough to run the
>> oscillator with its heater and the main VE2ZAZ input - the two
>> low-current outputs could be set to +5 and -5 and provided to the VE2ZAZ
>> output circuit.
>>
>> It *is* possible to start with a single-voltage DC supply, and generate
>> positive and negative voltages from it.  It's a bit tricky.  One
>> approach is to use a switching-type "inverting regulator" to create the
>> negative voltage.  Alltronics has a +12 in, -5 out (Astec AA7600), $8
>> for two.  These switching inverters might not be a great solution for a
>> GPSDO where you want really low noise, though.
>>
>> Another approach is to start with something like a 24-volt DC supply,
>> and use a 7805 linear regulator to create an "artificial ground" (which
>> then becomes the "GND" power input to your VE2ZAZ board).
>>
>> If I were you I'd probably look for a multiple-output DC power supply...
>> Electronics Goldmine, Alltronics, All Electronics, Marlin P Jones are
>> all good on-line vendors to check.
>>
>> And... as an out-of-the-box possibility - although your HP oscillator
>> has a -5 to +5 tuning range, there's no law that says you have to
>> actually *use* the whole tuning range.  You could have the VE2ZAZ board
>> put out a tuning voltage between 0 and 5 (so no negative supply
>> required) and use the HP oscillator's "FREQ ADJUST" trimmer to
>> rough-tune the oscillator so that it's right about on-frequency when the
>> VE2ZAZ is feeding a mid-scale output (2.5 volts) to the oscillator's
>> EFC input.
>>
>> This would let you get away with just positive power supply voltages to
>> the oscillator oven, oscillator input, and VE2ZAZ.
>>
>>
>>
>> ______________________________________________________________
>> GPS_Standard mailing list
>> Home:http://mailman.qth.net/mailman/listinfo/gps_standard
>> Help:http://mailman.qth.net/mmfaq.htm
>> Post:mailto:GPS_Standard at mailman.qth.net
>>
>> This list hosted by:http://www.qsl.net
>> Please help support this email list:http://www.qsl.net/donate.html
>>
>
>
>
>
>
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>
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>
> End of GPS_Standard Digest, Vol 69, Issue 2
> *******************************************
>