| Restocking Fee | No |
|---|---|
| All returns accepted | Returns Accepted |
| Item must be returned within | 30 Days |
| Refund will be given as | Money back or replacement (buyer's choice) |
| Return shipping will be paid by | Buyer |
| Brand | M-Tron |
| Model | MH-131 |
| MPN | 14.1381 MHz |
Check the listing for details. (4) 20-Meter QRP Oscillators - 1/2 size Shielded Metal Can with DIP-8 footprint. Condition: Open box. Listed at 11.95 USD. General / Advanced / Extra Class 20 Meter QRP Transmitter - 14.318 MHz 1207 Most purchases qualify for a ** Combined Shipping Discount ** Fast eMail Fast Shipping Guaranteed Good-on-Arrival Price is for (4) miniature QRP Oscillators See application info on CW, MCW and even AM modes below! Amateur Radio HAMs, get a 20 Meter QRP NET on the air FAST and SIMPLE with these self contained low-power "transmitters". Sold in lots of (4) units. These are clock oscillators in a fully shielded DIP-8 size metal can. The nominal 14.318 MHz frequency falls nicely in the upper half of the 20 Meter HAM Phone band available to all G,A,E Class HAMs (14.225 to 14.350 MHz). If your receiver has a product detector or BFO, use these in CW (Carrier) Mode. You can identify different stations by the slight variations in frequency. If you are using an AM-only receiver, just add a simple modulator, such as the linked example below, for MCW (Modulated CW). Choose different values of resistors and capacitors for different tones. SIMPLE WIRING Standard CW Mode: Just ground pin 4, connect a LPF and/or antenna to pin 5 and key +5 VDC to pin 8 (shown below) and you're on the air. (Add a 0.001µF bypass directly across pins 4 & 8 for improved oscillator stability.) Can't get any simpler! LONG RANGE Of course range varies widely and avid QRP'ers know that it's the Antenna, Antenna, Antenna that is the key. But as an example, I've had 6M and 10M units on the road, using a short wire antenna draped over the car seat, reach out over 1½ miles to a receiver connected to a roof level vertical. I imagine these will perform similarly. But the real possibilities come from elevated antennas on both ends, especially beams. AMPLITUDE MODULATION AM operation is easy with the addition of a small audio transformer. (Transformers are available in our other listings.) The example to the right will work with any audio source intended to drive a speaker. Note the reversal of PRI and SEC windings. The impedances are not critical and almost anything close will work. Optional Low Pass Filter (LPF) The harmonics are weak, but you can construct your own filter if you experience interference with nearby equipment. (This plan is for informational purposes only. This auction does NOT include LPF parts.) The cutoff is well below the 2nd harmonic but with a wide buffer zone so loose part tolerances won't threaten clipping the fundamental frequency. The 0.66 µH air core inductors can be handmade by close-winding 15T #22 on a ¼" form. For other wire sizes and/or coil dimensions there are Air Coil Inductance Calculators on the internet to 'roll your own'. Other possibilities: Fox Hunt Beacon Telemetry Model Rocket or Balloon Payload Add a divide by 2 IC* circuit for a 40 Meter HAM band output. Add a divide by 4 IC* circuit for a 80 Meter HAM band output. Add an LPF and a small amp on your band of choice for a serious QRP transmitter. * Note: a 74LS74 or equivalent binary divider is recommended. 160, 80, 40, 10, 6 and other 20 Meter oscillators available. Check our other listings or e-Mail us. Note: Configurations and applications vary and performance varies. Please review FCC Part 15 and Part 97 if you are not certain your particular use is in compliance. The suggestions above are not intended to promote illegal or improper use. It is the amateur's responsibility to ensure the completed transmitter is in compliance and that it's operation does not interfere with other equipment. Q20C-4 ************************************* ham radio etronic e-tronic hamtronic qba BootsParts USA boots PAYMENT and SHIPPING ** We offer a Combined Shipping Discount for most purchases (excluding books) if paid with ONE SINGLE PAYMENT with eBay's SHOPPING CART ** Condition of Goods Unless otherwise noted above: NOS (New Old Stock) or better, clean, unused 30 day Non-DOA, Good-on-Arrival Guarantee Untested, but NO JUNK or suspect parts PCB parts are thru-hole, NO SMD/SMT Small parts may be bulk packed Manufacturers and Date Codes may vary Attention International bidders only: Sorry, we ship to US ZIP Codes ONLY. We DO NOT ship Internationally. We ONLY ship to Registered US PayPal addresses. We DO NOT accept INTERNATIONAL PayPal payments. IMPORTANT: The parts we sell are categorized as new because they are unused, but many of our parts are those rare, hard-to-find, discontinued, manufacturing surplus and / or old stock commonly known in the parts business as 'NOS' (New Old Stock). Some of our stock pictures show date codes which may vary from the actual product shipped. Parts from a larger OEM package may be repacked for smaller lot size orders or for more practical handling and shipping. We strive to give full and accurate descriptions to earn your 5-Star Feedback. Any known deficiencies are listed in the detailed description. Datasheets are provided when available. Some datasheets may be close but not a perfect match because of part revisions or because they may be from a different manufacturer. If you have any questions concerning our products please email us before purchasing. Your complete satisfaction is important to us before and after the sale. Thank you.