In a moment of carelessness, I inadvertently transmitted into the RX input of
my recently acquired TR-7 while testing the transmitter output last week.
OK - I can hear the laughter now, and it is well deserved!
So far I have determined:
The rig had zero (or near zero) RF output when purchased
How, exactly, did you transmit into the Rx. The up converter board is also part
of the transmit chain?
The Ext RX Ant socket would have been isolated by the T/R relay.
On 23-Apr-10 11:20, Charles Kaross wrote:
In a moment of carelessness, I inadvertently transmitted into the RX
input of my
That mixer is in both the Rx and Tx path so will result in no output if faulty.
Replace it with a Mini-Circuits SRA-3MH.
See http://www.sm6rpz.se/radio/mod7.php
On 23-Apr-10 11:20, Charles Kaross wrote:
The rig had zero (or near zero) RF output when purchased - I will move
this problem to
The closest replacement for the VARI-L mixer used in the TR7 is the
Mini-Circuits SRA-3MH+. The SRA-1 is a 7dbm LO mixer and the LO in
the TR7 is right at 13dbm.
http://www.minicircuits.com/products/fm_pic_level_13.html
Also check the 2 pin diodes, CR1401, CR1402, MPN3404 at the front of
the
Thanks to all who replied with suggestions on the replacement mixer, etc.
I will probably go with the SBL-1MH+ if I can amend my order from RF parts.
How this damage was done involved using the wattmeter in a Kenwood antenna
tuner and a separate dummy load to check for TX output.
When I saw no
Joe, the SRA-3MH+ must be a newer version or product.It
has been three years since I last bought several of the
modules. I know the SBL-1MH+ works fine, but that newer
version should be a little bit better according to the
specifications.
Ron
_
From:
I did do some of the Zener bypassing, but did not measure the results. It
didn't make things any worse, I will say that, and I have pretty good MDS
numbers on my 7. In addition, I also bypassed the 3-terminal regulator ICs to
manufacturer's spec with some surface mount caps on the legs of the IC
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