starman wrote in message ...

There are differing opinions on how well the R-75 sync' detector works
after the mod'. It certainly works better, but compared to the sync' on
some other receivers, it's nothing to brag about.
My R75 sync det working performance is excellent [after the 339
comparator sync mod] at reducing distortion caused by selective
fading,as well as at diminishing or eliminating adjacent-channel
interference, You can select the better side band [in SAM sync mode
manually, using the TWIN PBT].This is not an oppinion but a
fact.Nothing to "brag about" but to use, when needed.I don't need to
compare it with other receivers sync in the market because it is doing
what is supposed to do very well..I had first hand experience with
some of the best sync det in the market as an owner of a Drake R8B,Sat
800 and the Sony 2010.
Ken

Were can I find out about these mods and what they do?

Dan



On 1 May 2004 10:03:59 -0700, (Kenneth) wrote:

starman wrote in message ...

There are differing opinions on how well the R-75 sync' detector works
after the mod'. It certainly works better, but compared to the sync' on
some other receivers, it's nothing to brag about.
My R75 sync det working performance is excellent [after the 339
comparator sync mod] at reducing distortion caused by selective
fading,as well as at diminishing or eliminating adjacent-channel
interference, You can select the better side band [in SAM sync mode
manually, using the TWIN PBT].This is not an oppinion but a
fact.Nothing to "brag about" but to use, when needed.I don't need to
compare it with other receivers sync in the market because it is doing
what is supposed to do very well..I had first hand experience with
some of the best sync det in the market as an owner of a Drake R8B,Sat
800 and the Sony 2010.
Ken

Dan Graves wrote in message . ..
Were can I find out about these mods and what they do?

Dan
Hi Dan You can find the Icom R75 mod's information he
http://groups.yahoo.com/group/icomr75/files/R75%20mods/
About your 2nd question:The sync upgrades provides enhanced
performance where the PLL stays "locked" under the most difficult
signal conditions.For example the KIWA sync upgrade is best described
as a "dual speed control voltage". The control voltage for the PLL
filter is tuned within an optimum window that is determined by signal
conditions.The response is slow to maintain a "centered" condition. A
second circuit provides the control accuracy to react to fast flutter
fading and noisey conditions. These two circuits provide a dual speed
control for the PLL.
The second major upgrade is to the Synchronous AM AGC. The dual speed
technique is used again to first center the AGC but still allow for
quick short changes in AGC characteristics as required by signal
conditions.In the files you can find others nice mods and tips for
enhancing the performance of your Icom. Ken

Dan Graves wrote in message . ..
Were can I find out about these mods and what they do?

Dan
Hi Dan: you can find the Icom R75 mod's information he
http://groups.yahoo.com/group/icomr75/files/R75%20mods/
About your 2nd question:The sync upgrades provides enhanced
performance where the PLL stays "locked" under the most difficult
signal conditions.For example the KIWA sync upgrade is best described
as a "dual speed control voltage". The control voltage for the PLL
filter is tuned within an optimum window that is determined by signal
conditions.The response is slow to maintain a "centered" condition. A
second circuit provides the control accuracy to react to fast flutter
fading and noisey conditions. These two circuits provide a dual speed
control for the PLL.
The second major upgrade is to the Synchronous AM AGC. The dual speed
technique is used again to first center the AGC but still allow for
quick short changes in AGC characteristics as required by signal
conditions.In the files you can find others nice mods and tips for
enhancing the performance of your Icom. Ken