‘Blog’ Category

ForSale – Heath 1277 PULSE GENERATOR

FOR SALE: Heath model 1277 Pulse Generator — $55 total, includes free ship to USA lower 48 states.
(aka Heathkit)

Photo shows unit outputting a delayed pulse. I have NOT tested all functions, therefore it is possibly that some repairs and-or calibration may be required. No manual or cables are included.

Front panel is nice condition in my opinion. Case has some scratches from other test equipment having been stacked on top.


Heath PULSE GENERATOR model 1277 as-is $55 free ship USA

FOR SALE rebuilt Heathkit IG-72 Audio Generator

beautiful and rebuilt HEATHKIT IG-72 Audio Generator$179 free ship inside continental USA

Here is a Heathkit IG-72 audio sine-wave generator, ideal for testing tube audiophile amps and guitar amps. This is a quality model that has an excellent low distortion sine wave for tube amp testing. And beautiful original cosmetics.

Rebuilt electronics, consisting of:

  • new capacitors (including correct orientation of caps regarding foil side of the caps)
  • upgraded the 5k-20W resistor to a 50W surface-mounted unit, for cool operation
  • meter smoothing capacitor
  • many resistors replaced to bring circuit into excellent overall accuracy
  • clean sine wave on all frequencies.
  • 3 wire grounded line cord installed to meet modern safety standards

I have attempted to photograph the sine wave below.  The sine wave looks better in-person than the photos show because my  camera has a tendency to bloom the scope trace.  (Photography is not my specialty!)

Paypal BUY-IT button here.

Heathkit IG72 audio generator $179 free ship USA


Q&A regarding different micromhos scores

Hey Tubesound,

Hoping you can answer a question for me. I have an Amplitrex and a TV-7D/U tube tester.  The Amplitrex tests a 12ax7 as new at 1600GM.  According to your TV7 GM calculator, I believe that should translate to 64 on the TV meter.  However, when I test the same 12ax7 on my TV-7 the meter only hits 42.  Does it sound like my TV7 needs some calibrating or am I missing something? Hope you can help and thanks for the great calculator.


Q&A regarding HP Officejet R-series repair

Q&A regarding HP Officejet R-series repair:


I have your article on “Repairing HP Officejet R-series”.  I used it several years ago; cleaning  the mirror fixed the problem.

I’ve lost flexible use of my hands so I wanted to get someone to do the service (suspect it needs cleaning and new bulb).  Local repair services refuse to work on ink jets.

Do you have a recommendation for help in the south NJ area?

Thanks, Jim


repair broken TP-Link TD-8616 ADSL modem

If you are trying to fix a TP-Link TD-8616 modem, chances are good that this is your problem.

On May 21, 2012, I purchased from Newegg a new TP-Link ADSL TD-8616 DSL modem to replace a very old Westell modem that was supplied by Verizon. At that time, the reviews for this product were overwhelming positive. Less than two years later, this TP-Link modem is already broken, and I see that recent reviews are more up and down.

Simply put, this modem had garbage capacitors, which is a common quality-control manufacturing problem with modern electronics.

Symptoms: for the past several months, connection was erratic, sync erratic, speeds fluctuating. Unable to connect to modem admin via TCP-IP.

Repair was as follows: (more…)

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