Thread: HDS 7 touch help

Please excuse the HB depiction ... But it serves the same reason of discussion ...(And it's basically the same info as cane pole has already posted) ...



Although Lowrance doesn't advertise their SI beam angle specs ...most opinions agree that the total SI coverage in the Lowrance Structure Scan is approximately 130° for the 800kHz SI beam ...

General piezo design of "Dual Frequency piezoes" usually creates the scenario where the lower frequency sound pulse (fired thru the same piezo) will create a somewhat wider coverage angle spec ...

Again... Lowrance doesn't publish this spec ...but we can garner from this theory that the lower frequency will generally have more range (due to wider angle) than the higher frequency (we guess this at about 150° total coverage)... (Thus Monte's idea that he sees farther with the lower frequency 455kHz) ...

The "other" factor in "Dual Frequency" piezo design is that higher frequencies will always render more detail than lower frequencies thru the same piezo ... (Thus ibmack's idea that he sees better detail with the higher frequency 800kHz) ...

Now even more "other" factors ...

Enviromental variables will always have a huge factor on the range effectiveness in all SI images (regardless of brand) ...

*Water particulate will absorb some of the sound pulse ...leaving less pulse strength to return to the xducer ...
*Soft bottom composition will absorb some of the sound pulse ...leaving less pulse strength to return to the xducer ...

The range limitation in the Lowrance Structure Scan SI is no more (nor less) than the facts of sonar sound wave theory ...and its properties as influenced by the underwater Enviromental variables ...

The only "controllable" factor lies in the specific piezo design for its "Dual Frequency" piezo ...(which is limited to approximately 150° total coverage simply because of patents held by HB ...as far as any information I can find) ...

Rickie