DFD4for superheterodyne radio applications in the VHF and UHF bands.
DFD4A for test equipment.
DFD4 has a built-in prescaler good to more than 2 GHz.
DFD4 has 4 operation modes.
The mode is displayed for a moment whenever it is changed.
IF offset is programmable from +/- 0 to 2GHz in 1KHz steps. (For test equipment applications order DFD4A))
How to order? Click here
kit version, $49.95, you install and calibrate it against WWV.
Example of DFD4 as a bench top frequency counter
DFD4 can be configured as a bench top frequency counter usable from 0 Hz to more than 2 GHz.
If that is what you intend to use DFD4 for then check out DFD4A
All thats needed is 3 switches, two resistors and two RF connectors from Radio Shack
Controls Kit add $5.00includes SPST ON/OFF switch, SPDT FAST/SLOW switch, DPDT HF/UHF switch and two BNC connectors a 10K and 20K resistor. Everything needed to implement the counter shown above..
Here's how one customer packaged his in a radio shack instrument case.
He comments also:
Building the DFD4 as a bench counter requires two resistors such as 10k
20k, or 10k and 5k, or whatever as long as one is 1/2 the value of the
second... well, what I did since I didn't have any 20k resistors, or 5k for
that matter was to use three identical 10k resistors that tested very
closely in value. I put two in parallel to get the 1/2 value. Mentioning
this might make assembly simpler for those that don't think of it and can't
buy two values (one half the value of the other) at Radio Shack. :-)
LED Backlit Display module also available.
Backlit displays to not fit the counter box kit. You will have to build your own enclosure to use them or the biggy display
This module is the same size as the non-backlit module and replaces it directly. You will have to supply a dropping resistor to set the current from your primary power source. The forward voltage drop of the LEDs is 4V and the maximum current is 200ma. The unit lites up pretty good with 30ma. At this setting it can be powered continuously from the on-board 5V regulator through a 33ohm 1/4 watt resistor. From 12V you need an 80ohm/2W resistor for 100ma, or a 160ohm/1W resistor for 50ma.
For LED backlit module instead of regular module add $7.50
BIGGY lcd display module option
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View DFD4 Instruction Manual
How to Order
By Phone with Visa/MasterCard
By FAX with Visa/MasterCard
By Mail Almost All Digital Electronics, 1412 Elm St. S.E., Auburn, WA 98092
L/C Meter II
DFD1 for single conversion and direct conversion
DFD2 for crystal controlled converters in front of tunable IF
DFD3 multi use user programmable unit (auto-programs itself for many radios)
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