EMRFD Message Archive 5383
Message Date From Subject 5383 2010-10-18 11:04:24 Gian AOR Proto AR7070 Hi all,
Imagine there are still people fiddling with "classic" conversion HF receivers !
Martein, PA3AKE, has just updated his web site to show the test results of the AR7070 up conversion radio.
The AR7070 has been designed by John Thorpe the designer of the highly acclaimed AR7030 HF receiver and also the designer of the 'HF' series of receivers made in Matlock by Lowe Electronics in the late 1980s and early 1990s.
IP3 dynamic range at 200Hz is 97 dB with an IP3 of 19dBm in a 2.4 KHz bandwidth. This rises to 115dBm at 50 KHz with IP3s around 46 dBm. The receiver has good sensitivity with no preamplifier before the first H mode mixer so for the 7Mhz band running with a 5 dB attenuator would put IP3 over 50dBm.
Martein presents in tabular form all the performance measurements that have been made by John Thorpe the radio's designer. There are also comments by Colin Horrabin, G3SBI and Martein.
Basically this receiver is an up conversion CDG2000 receiver.
To illustrate a particular point the AR7070 is compared with the review, by Peter Hart G3SJX, of the Yaesu FTDX5000 measured close in IP3 on the 7MHz band using the down conversion receiver. He did these tests with different roofing filter bandwidths. The test, using a 15 KHz wide filter, clearly showed that the IP3 within the roofing filter bandwidth was only -8.5 dBm. With the receiver noise figure being around 20 dB this gives a close in IP3 dynamic range of only 77dB compared to the AR7070s IP3 +19 dBm and 97 dB dynamic range in an SSB bandwidth.
Take a look at the results and you will be surprised:
It should prove to be the best up conversion radio of all time.
5386 2010-10-23 01:54:33 ha5rxz Re: AOR Proto AR7070 Nice to see that up conversi