K6JRF's Page
formerly W6FZC
FT1000D Transmit Carrier Point (TCP) Page
(Updated: Mar 5, 2001)

This TCP Page details the required adjustments to the FT1000D transmit carrier point to take full advantage of the wider InRad crystal filters and capacitor changes. Note 3 details all of this.
The detailed 'how-to-do' instructions for the TCP adjustment are contained in the table entitled "TCP Adjustment for Highest Frequency Offset".

NOTE 3 This report details the radio carrier set point adjustment using the modified TCP procedure for the new InRad filters (#715 and #716) in the FT1000D. When the InRad filters were installed the low frequency response was, to say the least, overpowering!! The attached graph (FTaud1f.gif) shows the results of the modified TCP adjustment BEFORE (old Yaesu filters) and AFTER (new InRad plus TCP adjustment). Note that the extreme low frequency response has been 'shifted' upward to gain the added high frequency response.

Radio Adjustment with Modified TCP Procedure:
This procedure is modified from the TCP procedure outlined in the FT1000D Service Manual, page 15. The intent is to end up with 'enough' low frequency response but to get as much high frequency audio response as possible. You may of course like to have a bit more low frequency audio response, so feel free to change the low frequency limit as necessary. However after listening to the results of my adjustment, no lower response is needed. Some may want to move the TCP to around 100 hz to gain as much high frequency audio response as possible with minimal effect on lower frequencies.

Some have asked . . "do I need to change the audio capacitors on the AF UNIT board if I install the new InRad filters? Won't the new filters give me the required audio bandwidth without making the changes"?
The answer is NO!! Without changing of the AF UNIT Board's capacitors, the low end frequency response cannot be pushed down since all audio low frequency information is cut off due to the values of these capacitors.

The following measurements are courtesy of W6RU. He installed the InRad filters into a stock FT1000D that did NOT HAVE THE AUDIO CAP MODS until they were added at the 3rd last measurement (in GREEN) in the table below. Note that the low frequency response could NOT be obtained until the cap changes were made. Lastly, I've included my radio's present response for contrast. Note the difference in the filters employed.
Description -3db Lower -3db Upper
stock FT1000D radio 325 hz 2605 hz
radio with NO filters + adj TCP 260 hz 2550 hz
radio with filters* + TCP 264 hz 2745 hz
radio with filters* + TCP + caps 87 hz 2835 hz
K6JRF radio with filters** + TCP + caps 95 hz 3075 hz
K6JRF radio with filters*** + TCP + caps 105 hz 3150 hz

* = Filters are InRad #715 and InRad #716
** = Filters are Murata CFS455F and InRad #716
*** = Filters are Collins CMF (InRad 707C) and InRad #716
To see how the Collins filter was chosen, please read Note [7]

In summary, there are THREE (3) procedures necessary to change the FT-1000D's audio. They are;
1) replace present filters with two (2) InRad filters on the IF FILTER board,
2) change four (4) audio capacitor values on the AF UNIT board,
3) adjust the carrier offset via the TCP adjustment on the LOCAL UNIT board as outlined below.

Update: 3/5/2001
W8CQ, Jeff sent me data showing the results on his FT1000D with both InRad filters (715, 716) along with the 'cap' mods plus TCP adjustment all summarized in one great chart. Good job, Jeff!

Results of FT1000D mods by W8CQ

The replacement of one InRad filter (#715) with an InRad #707 filter (Collins Mechanical Filter would increase the low and high frequency response as shown in table above (in RED).

TCP Results

The results of the TCP adjustment is shown here. Note that a audio signal generator or a set of pre-recorded tones (100hz and 3100hz is all that's necessary) to make this adjustment. The input signal is fed into the standard 8 pin mic connector and adjusted according to the directions provided.
The object is to obtain the greatest amount of high frequency response while balancing that with the low frequency response. The scales should be tilted in favor of high frequency response.

To make the highest possible carrier offset adjustment, use this procedure.

TCP Adjustment for Highest Frequency Offset

Do not perform this adjustment if you are not sure of what you are doing!!!

By adjusting the TC4001, L4071 and the two (2) capacitive trimmers, TC4006 and TC4007, you can offset the 8.2Mhz filter (InRad #716) to the highest possible point that the radio will allow. This procedure is described here.

Refer to the FT1000 Service Manual, page 4-15 for details of the TCP adjustment. I use my Sony MD with a previously recorded set of tones: 100hz and 3100hz which I feed into the mic jack input. You can also use a signal generator but the MD technique is much faster and accurate. Also required is a output power meter that you can easily see while doing this adjustment. Set the FT1000D power output control to about 1pm and mic gain at 10am.

As you make adjustments, monitor the power output from the radio for each tone. This is a relative adjustment so trying to get the highest power out at BOTH frequencies (100, 3100hz) is not important. In fact when finished, you should see higher power out at 3100hz than at 100hz by about 3dB. If you don't, then the adjustment is not complete.

1) With the front panel hinged down, the radio at 14.2Mhz, USB selected, adjust the TC4006 for the highest offset frequency. Then adjust L4071 to move it up even further. Then readjust TC4006. Do this while exciting with 3100hz.
2) Select LSB; most likely the power is way down. Adjust TC4007 for the highest offset. Then adjust L4071 back a bit in the opposite direction from the first adjustment) to bring up the LSB output power. Readjust TC4007.
3) Select USB; Perform step 1) again but this time use an educated guess as to where to set L4071 to get a balance (ie, equal power out) point that BOTH sidebands can attain at 3100hz.
4) Select USB; Adjust TC4001 slightly to see if USB power goes up. If so, then repeat step 1) and 2) making small adjustments while switching back and forth between USB and LSB AND switching 100hz and 3100hz tones!

Put the metal caps back on to each section and raise the front panel. Let it sit that way until it fully warms up. The adjustments will change slightly and need to be lightly 'tweaked' again.

The signal generator was found to be 150hz off at 3Khz and around 20hz at 100 hz so the frequency data in the X axis is not quite correct. You need to mentally add the correction factors. After receiving SpectraPlus, the signal generator was recalibrated to remove this error. The SP plots are, of course, correct.

Power Out vs Frequency after TCP Procedure

Sinewave Tx Response using Various Filters

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