AR88 - listening to SSB - UK Vintage Radio Repair and Restoration Discussion Forum

JanWra1 · 21st Nov 2018, 4:46 pm

Hi guys

When listening to SSB signals own my AR88D I have noted that the position of the BFO knob is in more or less the same position regardless of whether I listen to LSB or USB. Is this normal for these radios?
Comments pls.

Jan

G6Tanuki · 21st Nov 2018, 5:01 pm

What position have you got the 'Selectivity' switch in?

The first 2 positions are really wide (really intended for listening to AM broadcasts in good/reasonable quality) - so a SSB signal can be tuned-in 'somewhere' within the passband and the BFO set either side to match.

On mine, I generally found position 3 to be best for SSB - it's a lot narrower because the crystal-filter's in circuit - and then it _does_ matter which side you set the BFO.

Hartley118 · 21st Nov 2018, 5:56 pm

On my AR88, the BFO injection is pretty weak, so I find that I need to back off the manual RF gain control so that the signal level of the received station is similar to that of the BFO. Gain make-up is then achieved by increasing AF gain.

Martin

G6Tanuki · 21st Nov 2018, 6:00 pm

Definitely.

AGC set to Off. AF gain turned fully-up, control the signal levels using RF Gain.

JanWra1 · 21st Nov 2018, 6:40 pm

Thanks your inputs,
I use the RF and AF gains as you advise and Selectivity is usually on 3 however I have also got usable SSb in positions 4 and 5 the later for S9+++ signals.

Jan

21st Nov 2018, 4:46 pm	#1
JanWra1 Tetrode Join Date: Jan 2018 Location: Stockholm, Sweden Posts: 78	AR88 - listening to SSB Hi guys When listening to SSB signals own my AR88D I have noted that the position of the BFO knob is in more or less the same position regardless of whether I listen to LSB or USB. Is this normal for these radios? Comments pls. Jan

21st Nov 2018, 5:01 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: AR88 - listening to SSB What position have you got the 'Selectivity' switch in? The first 2 positions are really wide (really intended for listening to AM broadcasts in good/reasonable quality) - so a SSB signal can be tuned-in 'somewhere' within the passband and the BFO set either side to match. On mine, I generally found position 3 to be best for SSB - it's a lot narrower because the crystal-filter's in circuit - and then it _does_ matter which side you set the BFO.

21st Nov 2018, 5:56 pm	#3
Hartley118 Nonode Join Date: Aug 2015 Location: Cambridge, Cambs. UK. Posts: 2,198	Re: AR88 - listening to SSB On my AR88, the BFO injection is pretty weak, so I find that I need to back off the manual RF gain control so that the signal level of the received station is similar to that of the BFO. Gain make-up is then achieved by increasing AF gain. Martin __________________ BVWS Member

21st Nov 2018, 6:00 pm	#4
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: AR88 - listening to SSB Definitely. AGC set to Off. AF gain turned fully-up, control the signal levels using RF Gain.

21st Nov 2018, 6:40 pm	#5
JanWra1 Tetrode Join Date: Jan 2018 Location: Stockholm, Sweden Posts: 78	Re: AR88 - listening to SSB Thanks your inputs, I use the RF and AF gains as you advise and Selectivity is usually on 3 however I have also got usable SSb in positions 4 and 5 the later for S9+++ signals. Jan