HP 410C VTVM, Solid State Vacuum tube voltmeter

For Auction: Hewlett Packard 410C Vacuum tube Voltmeter , solid state version, (With HP RF Probe). Measurement Ranges are:  DCVolts from 15mv to 1500v, DC current from 1.5ua to 150ma, resistance ranges are  .2 Ohms to 500 Megohms, AC voltage .5V to 300V, AC Band Width nominally 700mhz. DC Input Resistance; 100megohm. Input Z: DC Voltmeter: 100megohm, AC: 10megohm, decreasing gradually with higher frequencies.  .Refurbished unit. 

Extensive repairs to these units include;  Original vacuum tube/transistor amplifier board ( A3) replaced with a 100% Solid State New Amplifier board. Test leads replaced or repaired as necessary....cleaned, missing and corroded hardware replaced,  pc board connections cleaned,  Q1 (+6vdc regulator)  checked and replaced as needed..  Meter face  replaced if necessary. A7 ( power supply/interface) board and  A6 board  (calibration board) are brand new PC boards..

 A7 (power supply interface board) is Brand New (new design). ( NOTE: The new design A7 power supply/ interface board is now a solder-in as opposed to the original "slip-on-connector" style) The original "slip-on connector" design was prone to a never ending set of interconnection problems.  ****  This is a solid state version of the HP-410C. Case repainted HP Olive . AC Probe repaired or replaced; this unit is equipped with a Genuine HP AC ( Active RF) Probe with new TRIAX cable.  DC Probe may be the stock HP, or the HP 412A Style , depending on what we have in inventory. DC Zero control added to units that did not have that rear panel adjustment built in from the factory ( very small number).  

This unit has a brand new  A6 (calibration) board installed. The new A6 board uses  15 turn Bourns trimpots.  Calibration is smooth and with much higher resolution available as compared to the stock single turn HP potentiometers. External panels and meter "brow" re-painted. Panels repainted Olive, meter "brow" painted Light Grey.  Computer style AC cord connector installed (some units used a HP oval connector),  AC cord set furnished as part of sale.  Unit is NOT checked for 220VAC operation.  

No photo-chopper to cause shakey needle, sluggish readings and heat related drift. No vacuum tube to cause drift and heat, No high voltage components to burn up. Warm up time basically the time it takes to warm up the AC Probe (about 25 minutes to thermal stability) Very  low drift over time, low power consumption, no heat buildup, leave the unit powered up 24/7.  All this and more with the solid state 410C.

 Unit is operational, repaired  and calibrated using the HP Lab AC/DC Calibrator designed for this family of analog meters.  A unit that is calibrated using the HP Calibration equipment will provide accurate readings vs units that are "Sold As Is".  The  instruments we sell receive a thorough disassembly, cleaning, repair and calibration.  Resistance ranges are verified  with 1% resistors.

Serial Number of the unit you will receive is: [     807-09768     ]    Photo: [     THE UNIT YOU WILL RECEIVE       ]  

These instruments are lab-grade, easy to use and repair. They are rugged, accurate, have a design 100megohm input impedance, which makes them teriffic for low level signals and measurements that are not accurate unless very lightly loaded, (receiver AGC/AVC  lines come to mind).  They are  just as  useful in the ham shack ( helping to repair those great old boat anchor era electronics) as the lab or the classroom . The RF (AC) Probe (useful to 700mhz) is perfect for low level signal tracing in oscillators, mixers, and transmitter and receiver  RF circuitry of all kinds.

Someone pointed out that , technically speaking, this instrument is not a "vacuum tube" unit . True. However these units are referred to as "VTVM"'s or Vacuum tube voltmeters" because, at the begining of their lives, they did contain a vacuum tube. We decided to stick with the original description.

****** NEVER EVER ATTEMPT TO MEASURE AC LINE VOLTAGE WITH THIS INSTRUMENT, THE CASE IS AT AC GROUND AND DOING SO WILL DESTROY THE INSTRUMENT *****

 The bulk of the cost of this instrument is the active RF probe,whether the HP or Militarized versions. The cousin of this instrument, the HP 410B, while not nearly as modern looking, has a design input impedance of 122megohms, ( and an active RF Probe as well) , making  it a great lower cost alternative to the 410C.

 We custom fabricate  the little "spring gizmo" inside the RF Probe, that is used to connect the tube top pin with the nose of the probe housing.( Occasionally these go missing.)  We can supply replacement triax-cable when the HP triax on your instrument fails. See our web page "PRODUCTS PAGE"  for details.

We can supply BRAND NEW replacement **A6  , A7 and A3 board sets,** . as well as replacement meter face (scales) . Email  for details and see our website:    www.kiss-electronics.com      "Products" page.

All electronics are shipped FED EX or USPS and, occasionally, UPS. USPS AIR MAIL PARCEL POST on all International  (no surface International )shipments. Teleporter Terminal available for our Galactic customers. All shipments are  double boxed to ensure you receive an undamaged unit, and, damage claims are rarely paid on electronics that are not double boxed.            Shipping weight is approximately 45 pounds, double boxed.      If you have objections to our packing method or the costs involved, please do not bid.     We want you to receive an undamaged unit, so we go to great lengths to ensure, as much as possible, that you do.    For shipment estimates,** ( estimates do not include double boxing supplies) **please go to the USPS, or FED EX, or UPS websites and click on "calculate shipping" or "calculate postage".    Our ZIP CODE is 97113-9169.  Our goal is to Invoice you for your purchase within three (3) Business Days, and ship your purchase within three (3) Business Days of receipt of your payment into our bank.       ***** INTERNATIONAL BUYERS NOTE: YOU ARE RESPONSIBLE FOR CUSTOMS, DUTY AND IMPORT FEES, PLEASE CHECK WITH YOUR COUNTRY FOR APPLICABLE FEES. WE WILL NOT DECLARE MERCHANDISE TO BE "GIFTS".****

Once unit is shipped, we are no longer responsible for loss or damage.

PLEASE READ THIS ~~~~> *** Regardless of what the Ebay shipping calculator may calculate, or what Ebay May Tell you,  do NOT send any form of payment until we have sent you an invoice for the sale ***  

******NOTE:  10% INVOICE DISCOUNT WHEN THE "BUY IT NOW" FEATURE USED ****** 

*** All Sales Final *** No warranties or guarantees expressed or implied. No returns, no substitutions. Not certain you will like the instrument or don't know exactly what it does ? Please do not bid.

We provide after sale technical and parts support ,via email, for all of the units that we sell and for all that are listed on our web page.  Technical questions about vacuum tube test equipment, parts, repairs and usage ? Email us.

We also service all of the types of electronics that we sell. Write for price quotes.  

We repair/refurbish : URM 25/26, HP 410B,410C, HP 608 family ,HP200CD, Simpson 303,TS510 (608D military version), HP204C, HP 204D, HP 209A.

http://www.kiss-electronics.com/ <~~~~~~~~ Our Web Page

***** we buy 410C parts, dead units, bits and pieces ****