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Reviews For: International Radio (Inrad) Crystal Filters

Category: Filters, RF: bandpass, duplexer, lowpass, highpass, RFI/EMI

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Review Summary For : International Radio (Inrad) Crystal Filters
Reviews: 48MSRP: 115-155
Description:
Maker of OEM type IF filters for various transceivers. mailto: sales@inrad.net
Product is in production
More Info: http://www.inrad.net/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00484.8
K1VIP Rating: 2002-11-27
Inrad filters make a good radio better Time Owned: more than 12 months.
I first ordered a 2.1k crystal filter for my FT-847 on rx and thought the sound was a little narrow for my usage as a ragchewer. I then exchanged it with them for the 2.8k and BOY does this baby ROCK. Smooth sounding is the best way to describe it. Very nice people and great service. I then got the 2.8k for tx as well and have been getting great audio reports. It really make this radio shine and was the best upgrade for this radio for HF.
W9NRG
K8AG Rating: 2002-09-24
Special needs not sloughed off Time Owned: 0 to 3 months.
I am refurbishing a Yaesu FT-80C (which is like an FT-747GX with a metal case, but lacking certain features). One feature it lacked was a CW filter. I tried their 701 filter and it worked quite well. They were very polite and understood about the experimental nature of what I was doing. Very nice people.
PA1HR Rating: 2002-08-22
The best filters you can get! Time Owned: more than 12 months.

I have several IF-filters from Inrad in my FT-1000MP Mark V and the review is short and simple: "these filters are the best you can get!"

The shape factor of Inrad filters is excellent; most of them have a shape factor of 1.5, 1.6 or 1.7.

The sound of these filters is very good.

The technical service from George and the very kind and fast delivery from Georgia are excellent too.

In short: "Inrad is equivalent to excellent!"

Don't look any further; just choose Inrad. Enjoy yourself with these filters for many many years. You will not be disappointed in any way.

N8YV Rating: 2002-03-13
Great Icom Alternative!! Time Owned: 0 to 3 months.
I recently installed an INRAD #314 filter in my Icom rig. This filter is a 2.1-KHz bandwidth I-F stage crystal filter, with a shape factor of about 1.52:1 from -6 to -60 dB, according to their posted performance chart.

I chose this filter in place of the Icom FL-222, its nearest equivalent. I did this for two reasons: 1) I am not comfortable with the FL-222's 1.8-KHz passband. This is a bit "too" narrow for most of my SSB work, resulting in a "nasal" quality to the audio. 2) PRICE!
At $160.00 shipped (two-day arrival time!), it is nicely cheaper than the FL-222.

Having used Icom filters in three previous Icom rigs, I wanted a better option than the filters they offer for narrow SSB use. I am not disappointed with my choice of the INRAD! This filter meets my needs nearly to perfection! The audio passband is very well-chosen, allowing good intelligibility with the received signal.

Gone is the annoying "choked" sound that accompanies filtering of less than 2 KHz, yet the improvement in rejection over the stock 2.4-KHz filter in my rig is significant! The quality of construction and mechanical "fit" is excellent, too.

I am not implying that Icom's filters are of any lesser quality---they are excellent, at least in my experience---but the choice of available bandwidths in the Icom line-up leaves something to be desired in narrow-passband SSB filters.

The INRAD people have addressed this shortcoming in a VERY satisfactory way! Top-notch service, too! Highly recommended!
NI0C Rating: 2002-01-26
Great QRM fighting tool Time Owned: 0 to 3 months.
I recently replaced my stock Kenwood cascaded 270 Hz and 250 Hz filters with cascaded INRAD 250/125 Hz filters in my TS-850S. Am very pleased with the improved S/N ratio and selectivity with no ringing whatsoever. The 250 Hz filter for the 8.83MHz IF installed okay next to the Kenwood 1.8 KHz filter. I find that I don't really need my outboard MFJ DSP unit on CW, except for the additional audio output power it provides.
WB9YCJ Rating: 2002-01-26
125 Hz CW filter great ! Time Owned: 0 to 3 months.
I have bought three filters from them. The first two were 2.8 Khz SSB wide for my FT-1000D. What a pleasant sounding filter. Lets in more of the "treble" or high end content from those stations transmitting full audio such as from the Heil Goldline Mic.

Also, just bought a # 719C which is a 125 Hz CW filter for my "D". Not overly narrow and I can hear weak, as well as strong signals. Really makes a differance and lets me " slice out" other qrm. I recommend the # 719C in the FT-1000D for serious CW operators. As received, I had to send it back to them because it wasnt soldered to the plug-in board properly. Returned to me in a jiffy and works super! They also offer 125's for several high end radios (IC-781).
W1GI Rating: 2001-12-10
Inrad Time Owned: more than 12 months.

BTW; My experience with INRAD has always been positive. Recently they sold me boards for my TS-850's crystal positions. (I was able to buy some filters via E-Bay).

In the past it was a full complement of filters for an FT-901DM.
WD5FOX Rating: 2001-12-09
Great product-great service Time Owned: 6 to 12 months.
I purchased a SSB filter for my FT-847 and it has worked great. It really helps as the 847 needs some receive help. George is great to work with and I highly recommend his products and him as well! He goes out of his way to make you a satisfied customer.
WB9WHE Rating: 2001-07-27
Excellent company and superb customer service Time Owned: 3 to 6 months.
Bought an INRAD 2.5 Khz mechanical filter to replace the stock ceramic filter in my FT-847. It really is a "drop in" replacement. The INRAD staff was very nice, helpful, and easy with deal with. The filter arrived quickly. It is an excellent performer. Well worth the price for the significant inprovement in HF SSB RX selectivity. A significant improvement over the stock cereamic filter. Not only is it very good, but INRAD is $25.00 cheaper than other sources.

I have only excellent things to say about INRAD and its products. I just wish they offered a 2.4 Khz crystal filter for the FT-847, which would be an IDEAL filter width for us Non-contesters!
JAMES_BENEDICT_EX_N8FVJ Rating: 2001-07-07
Excellent Time Owned: 0 to 3 months.
The #756 and #757 2.4kHz InRad filters are superior to the stock TEN-TEC when the received signal is above the noise floor, especially true under severe noise and crowded band conditions! I did not state this on the review below. I was testing for weak SSB signals in the noise under fairly good band conditions (see below).

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Earlier 5-star review posted by JAMES_BENEDICT_EX_N8FVJ on 2001-06-30

First, I really enjoy having custom accessories available from aftermarket suppliers. The following InRad filters were tested in the TEN-TEC model OMNI V. Model #752- 2.1kHz for 9mHz I.F., model #756- 2.4kHz for 9mHz I.F., and model #757- 2.4kHz for 6.3 I.F. The InRad 2.4kHz filters were first compared to the stock Ten Tec 2.4kHz filters in each I.F. Next, the 756 & 757 InRad pair vs the InRad 752 and TEN-TEC at 6.3mHz I.F. Additionally, the InRad #756 vs stock TEN-TEC in series with #752.
The OMNI V has audio based filtering, thus I set the audio for best performance. The TEN-TEC 2.4kHz pair were better centered with the USB vs LSB test. Now, an adjustment on the PBT will correct for this- at least to my ears. I bought the filters for selectivity and weak signal performance. The Ten-Tec 2.4kHz pair were a little better on very weak signals without a strong signal nearby due to operating slightly more quiet- simply, less I.F. hiss. (The RF gain was set for best noise performance with each I.F. crystal set). As band conditions became more difficult with close-in signals, the gap closed. The InRad 2.4kHz at 6.3mHz with a stock Ten-Tec at 9mHz yielded the best weak signal performance of all- not a large difference, but slightly better. Now, inserting the InRad 2.1kHz in series at 9mhz with the stock Ten-Tec and InRad 2.4kHz at 6.3 I.F. made weak signal copy more difficult. The bandwidth 'information' was reduced and I.F. noise increased. Note- The In-Rad 2.4kHz pair sounds slightly more high frequency restricted than the TEN-TEC 2.4kHz pair. Simply, the InRads are more selective at the -6 db point. The next test was the Ten-Tec 2.4kHz at both I.F.s and the In-Rad 2.1kHz at the 9mHz I.F. This combination yielded a quiet I.F. and good weak signal copy. The weak signal copy is better than the 2.4kHz InRad pair. As band conditions became crowded, the gap closed slightly. Changing the TEN-TEC 9mHz with the In-Rad 2.4 on the above test degraded weak signal performance- more I.F. noise. I believe if the TEN-TEC 9mHz I.F. section gain was reduced, the InRad 2.4kHz filters would win the weak signal contest. As filters are designed more selective at the -6db point, the filters seem to 'ring' slightly more and increase I.F. hiss as observed in the OMNI V. The stock TEN-TEC 2.4s with the InRad 2.1kHz is hard to beat under weak signal copy. Keep in mind, the TEN-TEC has two I.F. gain adjustments at the narrow 9mHz I.F. filter slot- use the lower gain adjustment here for SSB signals. I rate the pair of InRad 2.4kHz filters with slightly less weak signal performance compared to the above test, however the gap narrows under crowded band conditions. Keep in mind, the above test adds another 8 poles of filtering. This is a 'oranges to apples' test! I believe the ultimate filter set up would be a InRad 2.8kHz at the 9mHz I.F., InRad 2.4kHz at the 9mHz narrow slot, a stock TEN-TEC 2.4kHz at the 6.3kHz I.F. (2.4kHz filter slot). Finally, an In-Rad 2.4kHz at the 6.3kHz I.F. (1.8kHz filter slot). The wider the first I.F. filter becomes, the quieter the I.F. generated noise, that is, in the OMNI V. I will comment on this when I receive the 2.8kHz filter. The 2.8kHz InRad filter in the 9mHz I.F. is in the SSB xmit circuit. On transmit the audio has been reported to be outstanding with approval from the HI-FI SSB crowd. The above filter set up does cost a few dollars. If one is limited in budget, then the optional InRad 2.1kHz filter with the stock TEN-TEC 2.4kHz filters is the low dollar winner! The above comments only relate to the OMNI V. Results on other TEN-TEC radios such as the OMNI VI or VI+ could not be concluded by this test. The OMNI V audio filtering will remove all filter ringing which degrades weak signal performance. Are the InRad filters a great addition to the OMNI V? YES! Thanks International Radio for some great products!