On Wed, 20 Jun 2018 09:52:08 -0700 (PDT), "
wrote:
On Wednesday, June 20, 2018 at 12:16:27 PM UTC-4, Jeff Liebermann wrote:
file:///C:/Users/pwieck/Downloads/8640B-Signal-Generator-Operating-and-Service-Manual-08640-90017.pdf
Ummm... that's the URL that points to your own c: drive.
There are downloadable HP8640 manuals all over the internet. However,
there are variations, packaging differences, options, and specialty
variations such as avionics or military versions. I think I have most
everything in PDF form and can snail mail a CD or arrange for you to
download them.
Give me the manual-seems to do about everything I want.
There is one that would be $350 FOB 19027, and with a 30-day full guarantee. Looks very clean.
Thoughts?
My pitch line is that you can get some really nice used HP RF
generators for little money. The danger is that it might be too old
to get parts, or have some well hidden problem that you don't
immediately notice. A 30 day guarantee is fine, but you pay shipping
both ways. At 45.8 lbs (20.8 kg), that's not cheap.
There are a few potential mechanical problems. The big one is that
the bevel gears in the frequency range and modulation rotary switch
mess are cracked. Someone makes replacement gears using 3D printing,
but I haven't seen them. I would prefer brass. I'm tempted to make
some but would need to buy an indexer for the mill that I'm sharing.
Here's what it looks like:
http://802.11junk.com/jeffl/pics/HP8640B/
I can explain how I fixed the gears later. The good news is that once
the hole in the plastic gear is enlarged to fit the brass ring, and
glued, it stays fixed.
Here's a list of some other potential problems and fixes. Some of my
stuff is mixed in there, somewhe
http://www.ve7ca.net/TstH86.htm
I have an HP8640b on the bench (or rather under the bench) that needs
a new RF output amplifier.
Check the options. Opt 1 and 2 involved the frequency ranges as
explained in:
http://electronicsrevisited.com/html/hp_8640b.html
Opt 4 is for avionics. You definitely want Opt 3, which is reverse
power protection. Without it, you run a good chance of accidentally
burning out the output attenuator. There's a 0.1A fuse in the N
connectors, but it's better to let Opt 3 protect the unit.
They don't make them like this any mo
http://802.11junk.com/jeffl/pics/HP8640B/slides/hp8640b-fix.html
However, I'm wondering if an HP8640B is what you really need. The
cavity oscillator is really low noise, which is what I need for SSB
noise and IMD measurements, but not much else. Perhaps a synthesized
generator might be better. I have an HP8656A generator:
https://www.ebay.com/sch/i.html?_nkw=hp8656+-Philips
Looks like the average selling price of $350 is over your limit:
https://www.ebay.com/sch/i.html?_nkw=hp8656+-Philips&LH_Sold=1&LH_Complete=1
Maybe haggling with the seller will drop the price into your range.
I have an HP8656A:
http://802.11junk.com/jeffl/pics/home/slides/test-equip-mess.html
Upper right, bottom of the pile on the shelf. Over the last 10(?)
years I had a few problem.
- The rear panel RF output connector is rather inconvenient.
- Calibrating the RF output, deviation, and AM modulation, were needed
after I screwed things up my not reading the instructions.
- The push buttons on the front panel tend to hit the front panel
bezel and stick. I'm sure I can fix it if I take it apart, but
haven't had the desire or time.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558