Description: Item Description: For sale today is one bare PCB for an oven stabilized 10MHz reference/timebase for frequency counters and function/signal generators that use a 10MHz reference. This is a new lot that was ordered due to the popularity of the original boards. The main differences between this board (Rev-B) and the original board (Rev-A) other than the green color is an op amp buffer between the reference pot and the OCXO control input, the silkscreen is annotated with the OCXO pinouts and the board will also will take two sizes of OCXO vs one size on the original. All information necessary to assemble the board is in the listing and the pictures. If the counter or function generator you have uses a crystal ring oscillator or even an oscillator module (not oven stabilized) this board will be much more accurate and stable. This board is not recommended for the HP/AGILENT 53131A, 53132A, or 53181A counters as they have an auto cal routine that uses a DAC. The board can work with 5V or 12V OCXOs and 5V or 12V supply voltage provided the appropriate reference IC is used. Condition: This is a bare PCB for DIY assembly. DIY Build Information: The user will have to be able to solder SMT parts to the PCB. All parts are size 0805 or larger for ease of assembly. The BOM calls out multiple 12VDC and 5V square wave output OCXOs. Others will also work if the footprints match. A precision reference IC and a 25 turn trim pot are used to adjust the frequency. The 0 ohm resistors on the schematic can be implemented with solder bridges across the pads. The OCXOs are available from multiple outlets on EBAY. The OCXO131-191 oven oscillator stabilizes within 2 to 3 minutes after turn ON but should be on for at least an hour for the final frequency adjustment. There is a test point on the board for ground and for measuring the OCXO trim voltage. This OCXO requires +12VDC at 340mA during startup and 140mA when the oven is at temperature. The fast startup allows for the counter to be OFF when not in use and powered when needed. It can also operate with a 5VDC OCXO if the reference is changed to 4.096V or less. Note, the larger package OCXOs like the 131-191 usually have better specifications than the smaller OCXOs like the OSC5A2B02. The board is 2.05" by 1.55" with four isolated mounting holes for 4-40 screws. Standoffs should be 3/16 hex. The mounting holes can also use KEYSTONE 2262-2 swaged standoffs (can be soldered in place). Standoffs and screws are not included. One picture shows the mounting hole spacing, but the board can also be used as a template. The small size allows for the ability to fit in many different instruments. How you connect the reference to the counter/generator is up to you. The output is a TTL compatible square wave for connection to a LSTTL or HCT CMOS input. The resistor divider on the output changes the OCXO's 6V P-P square wave to just under 5V P-P. You may have to tweak this depending on your counter's reference input impedance. The board has a hole pattern for an SMA connector for the output as shown in the assembly picture but the user could also hard wire a coax cable from the board to the counter. If you are going to calibrate this yourself, you will need an accurate and stable 10MHz reference clock such as a Rubidium reference oscillator or GPS stabilized reference. The counter will only be as good as the reference used for calibration. PayPal Confirmed Address: PayPal address must be confirmed and must be the same as the shipping address.Returns: All items are sold as-is unless otherwise stated. Returns: Returns accepted within 30 days. Feedback: Feedback is important to me, please email or contact me with any concerns, issues or problems before leaving feedback and give me the opportunity to work things out if needed. I always leave positive feedback after receiving feedback from the buyer, that way I know the buyer is happy and the transaction is complete. Shipping: Shipping is to USA or international via EBAY shipping service.
Price: 8 USD
Location: New Hartford, Connecticut
End Time: 2024-08-20T23:30:49.000Z
Shipping Cost: N/A USD
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Item Specifics
Return shipping will be paid by: Buyer
All returns accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
Brand: Unbranded/Generic
Model: N/A
MPN: Does Not Apply
