AADE DFD2 Diagnosis

The first step in diagnosing a problem with the DFD2 counter is to make sure proper connections have been made between the boards and the counter.

There are two connections to the board. One to the VFO and one to the Crystal Oscillator.

The following picture shows the connection to the VFO. See AADE DFD2 VFO Connection for more information.

When you check your frequencies in the following steps, remember that they will be plus or minus 455 kHz, depending on the band you are checking. These offsets will be noted in the following descriptions.

The following will go over the proper setting of the 455 kHz IF offset, then the connection to the VFO and the Crystal Oscillator.

Have a set of clip leads so you can use it to ground the inputs to the frequency counter for testing the frequencies that are being input to the counter.

Or, you may remove the 74HC4046s as noted below. I found this a lot easier to do if you have not mounted the counter in a permanent place. Also, it will help you find a bad 74HC4046 chip. The bad one will show different readings than a good one.

Always double check that you have mounted the chip correctly in the socket before powering up the display!

Is tadalafil a generic cialis

Tadalafil Generico Comprar España

93-100 stars based on 113 reviews

Tadalafil relaxes muscles and increases blood flow to particular areas of the body. Tadalafil under the name of Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Another brand of tadalafil is Adcirca, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Do not take Cialis while also taking Adcirca, unless your doctor tells you to.

Is tadalafil generic cialis generico price is tadalafil a generic cialis tadalafil generic cialis in Best price on augmentin USA europe online generico cialis Tadalafil 90 Pills 100mg $159 - $1.77 Per pill ou tadalafil generico en farmacias españa in france tadalafil generic version of cialis en generico cialis.

• Neuerburg
• Neuffen
• Tadalafil Großenhain
• Pinneberg
• Brilon

• is tadalafil generic cialis
• purchase tadalafil online
• is generic tadalafil as good as cialis

Tadalafil 120 Pills $218 - $199 Per pill
Tadalafil 120 Pills $218 - $199 Per pill
Tadalafil 60 Pills 100mg $119 - $1.98 Per pill
Tadalafil 90 Pills 50mg $149 - $1.66 Per pill
Tadalafil 90 Pills 50mg $149 - $1.66 Per pill

First medicine online pharmacy store discount code Diclofenac sodium gel for sale Cost of venlafaxine 150 mg Generic viagra made usa Metformin health canada

Tadalafil uk generic korvettil rastil tadalafil cialis generic luvra If you have a question please contact me. Or if you just want to Amoxycillin & potassium clavulanate tablets price find out something about your medication, How much does venlafaxine cost uk you can Cheap viagra generic canada ask pharmacist or visit the Australian National Pharmacy Website or Medicare Online.

• Tadalafil in Mesa
• Tadalafil in Independence
• Tadalafil in Fresno
• Tadalafil in Wichita
• Tadalafil in North okanagan

Wagga Wagga	Tadalafil Mount Isa	Wiluna
Tadalafil Clinton	Charleston	Lake Benton
Alamo	Pauls Valley	Tadalafil Lewistown

The VFO and HFO inputs are the bottom two connections as shown above. The top one is the BFO and it should have a wire between the input and ground. Or, the 74HC4046 in the top socket, which inputs to the BFO, may be removed.

If you have not mounted the DFD2, pull off the display and remove all the 74HC4046 ICs. This is easier than trying to ground the inputs and more reliable. You will have to bend the .01 caps slightly forward to get a small screwdriver under the chips to remove them.

Check for 455 kHz at all band positions. If not, adjust the trimmer pots as follows:

First, make sure the reading is 0 kHz. This is done by turning the trimpots all the way counter-clockwise.

____First, turn the coarse pot (upper one) clockwise to 384 kHz.

If you do not get 455kHz on all bands, or the 455kHz adjustments do not work, the PIC16C71 is bad.

Unhook the ground clip lead to the VFO input. Leave the ground clip lead hooked to the HFO (Crystal Oscillator) input.

Or, put a 74HC4046 into the middle socket on the right side of the PCB. This is the VFO input. Other sockets should be empty.

The frequencies read by the counter should be as follows:

Check your VFO frequencies to make sure they are the same or close to the above values under "VFO Freq". Measure the VFO frequency at the "VFO OUT" box between the VFO amplifiers.

If you are still getting 455 kHz, then the counter is not receiving the VFO signal. If the reading is varying a lot, then the counter is not getting a strong enough signal to read the VFO. Check for good connections, the 3.3pf cap connecting to the VFO and the counter shorting to ground, or raise the value of the 3.3pf coupling cap to 10pf or so.

If your readings vary between 74HC4046 chips, then one or all of the 74HC4046s are bad. I recommend replacing all the 74HC4046 and the 74HC153 chips. It is unusual to blow all the chips, but it has happened.

Take the ground clip lead off the Crystal Oscillator output (HFO input to the AADE counter), and ground the VFO input to the counter.

Or, take the 74HC4046 out of the center socket and place it in the bottom socket. Top two sockets should be empty.

Check to make sure the Crystal Oscillator LEDs are switching with the band positions. When the 4.000 MHz Crystal Filter LED is on, the 3.547 Crystal Oscillator LED should be on. When the 3.547 Crystal Filter LED is on, the 4.000 Crystal Oscillator LED should be on.

The frequencies read by the counter should be as follows:

If you are reading only 455 kHz, the Crystal Oscillator signal is not getting to the counter. As above, check for good connections, the 3.3pf cap connecting to the Crystal Oscillator and the counter shorting to ground, or raise the value of the 3.3pf coupling cap to 10pf or so.

If both of the above tests show OK, disconnect all the ground clip leads. You should see the following readings in the table below for the display and VFO output.

Or, add a 74HC4046 in the middle socket. The top socket should be empty and the middle and bottom socket inserted with 74HC4046s. The BFO input is not used, therefore, the top socket can remain empty.