[Lowfer] Group order FT-240 ferrite cores 77 and 78 material

[jrusgrove at comcast.net]

We did a group order several years back for FT-240-77 cores ... and a number of folks joined in. 
Although the deal isn't quite as good as last time it's still attractive compared to what the usual 
suppliers charge.

FT-240-77 @ $6.50 each

... plus a small portion of the overall inbound shipping ... plus outgoing shipping like Flat Rate 
Priority Mail for $4.95 which will cover about a half dozen cores. Note that these are offered at my 
cost - and the offer is limited to the group. Please don't disseminate this offer far and wide!

Also available

FT-240-78 @ $6.50 each

plus shipping as outlined above.

While working on a new Class D, 137 kHz, 4-FET kilowatt output amplifier I stumbled onto 78 material 
... (still wondering how it eluded me until now). At the kW power level the original 77 material 
output transformer (at > 1000g) was running pretty hot - albeit probably within spec. While looking 
for a larger 77 material core the 78 material data was discovered. Apparently 78 was developed 
specifically for 'high' power applications primarily in the 100 - 200 kHz frequency range ... 
although it is 'rated' through at least 750 kHz. The 78 material has about 1/4 the loss factor as 
compared to 77 material ... and, as expected, ran considerably cooler in the kW amplifier. See specs 
at the links below. I'll be replacing cores in my other Class D amplifiers and the antenna matching 
transformer with 78 material as soon as I get more cores.

If interested in getting in on the 'buy' e mail me direct with your needs and send along your 
mailing address. I plan on ordering cores early next week so don't dilly dally if you're interested.

77 material:

http://www.fair-rite.com/cgibin/catalog.pgm?THEONEPART=5977003801&SEARCHAGAIN=N#select:onepart

78 material:

http://www.fair-rite.com/cgibin/catalog.pgm?THEONEPART=5978003801&SEARCHAGAIN=N#select:onepart

Jay W1VD  WD2XNS  WE2XGR/2